[U-Boot] Pull request: u-boot-net.git master

Message ID	201905072215.x47MFDuv034108@osboxes.amer.corp.natinst.com
State	Changes Requested
Delegated to:	Tom Rini
Headers	show Return-Path: <u-boot-bounces@lists.denx.de> Message-Id: <201905072215.x47MFDuv034108@osboxes.amer.corp.natinst.com> Date: Tue, 07 May 2019 17:09:57 -0500 From: Joe Hershberger <joe.hershberger@ni.com> To: Tom Rini <trini@konsulko.com> Cc: u-boot <u-boot@lists.denx.de> Subject: [U-Boot] Pull request: u-boot-net.git master Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" <u-boot-bounces@lists.denx.de>
Series	[U-Boot] Pull request: u-boot-net.git master \| expand [U-Boot] Pull request: u-boot-net.git master

Joe Hershberger May 7, 2019, 10:09 p.m. UTC

Hi Tom,

The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:

I rebased on your master and built for BB Black. DHCP seems to work fine.
MLO also now fits again.

  Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)

are available in the git repository at:

  git://git.denx.de/u-boot-net.git master

for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:

  net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)

----------------------------------------------------------------
Carlo Caione (4):
      net: phy: Add generic helpers to access MMD PHY registers
      net: phy: ti: use generic helpers to access MMD registers
      cmd: mdio: Switch to generic helpers when accessing the registers
      net: phy: realtek: Introduce quirk to mark RXC not stoppable

James Byrne (2):
      net: phy: micrel: Use correct skew values on KSZ9021
      net: phy: micrel: Find Micrel PHY node correctly

Murali Karicheri (2):
      ARM: k2g-gp-evm: update to rgmii pinmux configuration
      ARM: k2g-ice: Add pinmux support for rgmii interface

Pankaj Bansal (1):
      drivers: net: ldpaa_eth: fix resource leak

Siva Durga Prasad Paladugu (2):
      net: phy: Reloc next and prev pointers inside phy_drivers
      net: phy: Fix return value check phy_probe

Valentin-catalin Neacsu (1):
      net: phy: aquantia: Set only autoneg on in register 4.c441

Vladimir Oltean (6):
      net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
      net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
      net: phy: ar803x: Use common functions for RGMII internal delays
      net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
      net: phy: ar803x: Explicitly disable RGMII delays
      net: phy: ar803x: Clarify the intention of ar8021_config

 arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
 arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
 arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
 arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
 arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
 arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
 arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
 board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
 cmd/mdio.c                                      |  27 +++--
 doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
 drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
 drivers/net/phy/Kconfig                         |  41 ++++++++
 drivers/net/phy/aquantia.c                      |   7 +-
 drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
 drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
 drivers/net/phy/phy.c                           |  21 +++-
 drivers/net/phy/realtek.c                       |  19 ++++
 drivers/net/phy/ti.c                            | 130 +++++-------------------
 include/phy.h                                   |  70 +++++++++++++
 19 files changed, 394 insertions(+), 221 deletions(-)

Thanks!
-Joe

Joe Hershberger May 8, 2019, 10:24 p.m. UTC | #1

On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>
> Hi Tom,
>
> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
>
> I rebased on your master and built for BB Black. DHCP seems to work fine.
> MLO also now fits again.
>
>   Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
>
> are available in the git repository at:
>
>   git://git.denx.de/u-boot-net.git master
>
> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
>
>   net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
>
> ----------------------------------------------------------------
> Carlo Caione (4):
>       net: phy: Add generic helpers to access MMD PHY registers
>       net: phy: ti: use generic helpers to access MMD registers
>       cmd: mdio: Switch to generic helpers when accessing the registers
>       net: phy: realtek: Introduce quirk to mark RXC not stoppable
>
> James Byrne (2):
>       net: phy: micrel: Use correct skew values on KSZ9021
>       net: phy: micrel: Find Micrel PHY node correctly
>
> Murali Karicheri (2):
>       ARM: k2g-gp-evm: update to rgmii pinmux configuration
>       ARM: k2g-ice: Add pinmux support for rgmii interface
>
> Pankaj Bansal (1):
>       drivers: net: ldpaa_eth: fix resource leak
>
> Siva Durga Prasad Paladugu (2):
>       net: phy: Reloc next and prev pointers inside phy_drivers
>       net: phy: Fix return value check phy_probe
>
> Valentin-catalin Neacsu (1):
>       net: phy: aquantia: Set only autoneg on in register 4.c441
>
> Vladimir Oltean (6):
>       net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
>       net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
>       net: phy: ar803x: Use common functions for RGMII internal delays
>       net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
>       net: phy: ar803x: Explicitly disable RGMII delays

Tom, this [1] is the patch that is breaking the evm. It doesn't affect
BB Black because it uses an SMSC phy, where as this evm uses an
AR8031/AR8033.

Is it possible the device tree [2] is wrong for the board? It lists
'phy-mode = "rgmii-txid";', so that means that with this patch the RX
delay is now being disabled.

Any thoughts, Vladimir?

Thanks,
-Joe

[1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
[2] arch/arm/dts/am335x-evm.dts

>       net: phy: ar803x: Clarify the intention of ar8021_config
>
>  arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
>  arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
>  arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
>  arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
>  arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
>  arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
>  arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
>  board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
>  cmd/mdio.c                                      |  27 +++--
>  doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
>  drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
>  drivers/net/phy/Kconfig                         |  41 ++++++++
>  drivers/net/phy/aquantia.c                      |   7 +-
>  drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
>  drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
>  drivers/net/phy/phy.c                           |  21 +++-
>  drivers/net/phy/realtek.c                       |  19 ++++
>  drivers/net/phy/ti.c                            | 130 +++++-------------------
>  include/phy.h                                   |  70 +++++++++++++
>  19 files changed, 394 insertions(+), 221 deletions(-)
>
> Thanks!
> -Joe
> _______________________________________________
> U-Boot mailing list
> U-Boot@lists.denx.de
> https://lists.denx.de/listinfo/u-boot

Tom Rini May 8, 2019, 10:37 p.m. UTC | #2

On Wed, May 08, 2019 at 10:24:29PM +0000, Joe Hershberger wrote:
> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> >
> > Hi Tom,
> >
> > The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> >
> > I rebased on your master and built for BB Black. DHCP seems to work fine.
> > MLO also now fits again.
> >
> >   Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> >
> > are available in the git repository at:
> >
> >   git://git.denx.de/u-boot-net.git master
> >
> > for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> >
> >   net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> >
> > ----------------------------------------------------------------
> > Carlo Caione (4):
> >       net: phy: Add generic helpers to access MMD PHY registers
> >       net: phy: ti: use generic helpers to access MMD registers
> >       cmd: mdio: Switch to generic helpers when accessing the registers
> >       net: phy: realtek: Introduce quirk to mark RXC not stoppable
> >
> > James Byrne (2):
> >       net: phy: micrel: Use correct skew values on KSZ9021
> >       net: phy: micrel: Find Micrel PHY node correctly
> >
> > Murali Karicheri (2):
> >       ARM: k2g-gp-evm: update to rgmii pinmux configuration
> >       ARM: k2g-ice: Add pinmux support for rgmii interface
> >
> > Pankaj Bansal (1):
> >       drivers: net: ldpaa_eth: fix resource leak
> >
> > Siva Durga Prasad Paladugu (2):
> >       net: phy: Reloc next and prev pointers inside phy_drivers
> >       net: phy: Fix return value check phy_probe
> >
> > Valentin-catalin Neacsu (1):
> >       net: phy: aquantia: Set only autoneg on in register 4.c441
> >
> > Vladimir Oltean (6):
> >       net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> >       net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> >       net: phy: ar803x: Use common functions for RGMII internal delays
> >       net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> >       net: phy: ar803x: Explicitly disable RGMII delays
> 
> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> BB Black because it uses an SMSC phy, where as this evm uses an
> AR8031/AR8033.
> 
> Is it possible the device tree [2] is wrong for the board? It lists
> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> delay is now being disabled.
> 
> Any thoughts, Vladimir?
> 
> Thanks,
> -Joe
> 
> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> [2] arch/arm/dts/am335x-evm.dts

Thanks for tracking this down.  I believe the DTS is right as it matches
the kernel in this regard.  That said, it's the Bone which has the
schematic available and not the EVM so I can't point at that for
further digging.

Vladimir Oltean May 8, 2019, 10:40 p.m. UTC | #3

On 5/9/19 1:24 AM, Joe Hershberger wrote:
> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>>
>> Hi Tom,
>>
>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
>>
>> I rebased on your master and built for BB Black. DHCP seems to work fine.
>> MLO also now fits again.
>>
>>    Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
>>
>> are available in the git repository at:
>>
>>    git://git.denx.de/u-boot-net.git master
>>
>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
>>
>>    net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
>>
>> ----------------------------------------------------------------
>> Carlo Caione (4):
>>        net: phy: Add generic helpers to access MMD PHY registers
>>        net: phy: ti: use generic helpers to access MMD registers
>>        cmd: mdio: Switch to generic helpers when accessing the registers
>>        net: phy: realtek: Introduce quirk to mark RXC not stoppable
>>
>> James Byrne (2):
>>        net: phy: micrel: Use correct skew values on KSZ9021
>>        net: phy: micrel: Find Micrel PHY node correctly
>>
>> Murali Karicheri (2):
>>        ARM: k2g-gp-evm: update to rgmii pinmux configuration
>>        ARM: k2g-ice: Add pinmux support for rgmii interface
>>
>> Pankaj Bansal (1):
>>        drivers: net: ldpaa_eth: fix resource leak
>>
>> Siva Durga Prasad Paladugu (2):
>>        net: phy: Reloc next and prev pointers inside phy_drivers
>>        net: phy: Fix return value check phy_probe
>>
>> Valentin-catalin Neacsu (1):
>>        net: phy: aquantia: Set only autoneg on in register 4.c441
>>
>> Vladimir Oltean (6):
>>        net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
>>        net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
>>        net: phy: ar803x: Use common functions for RGMII internal delays
>>        net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
>>        net: phy: ar803x: Explicitly disable RGMII delays
> 
> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> BB Black because it uses an SMSC phy, where as this evm uses an
> AR8031/AR8033.
> 
> Is it possible the device tree [2] is wrong for the board? It lists
> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> delay is now being disabled.
> 
> Any thoughts, Vladimir?
> 
> Thanks,
> -Joe
> 
> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> [2] arch/arm/dts/am335x-evm.dts
> 
>>        net: phy: ar803x: Clarify the intention of ar8021_config
>>
>>   arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
>>   arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
>>   arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
>>   arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
>>   arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
>>   arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
>>   arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
>>   board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
>>   cmd/mdio.c                                      |  27 +++--
>>   doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
>>   drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
>>   drivers/net/phy/Kconfig                         |  41 ++++++++
>>   drivers/net/phy/aquantia.c                      |   7 +-
>>   drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
>>   drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
>>   drivers/net/phy/phy.c                           |  21 +++-
>>   drivers/net/phy/realtek.c                       |  19 ++++
>>   drivers/net/phy/ti.c                            | 130 +++++-------------------
>>   include/phy.h                                   |  70 +++++++++++++
>>   19 files changed, 394 insertions(+), 221 deletions(-)
>>
>> Thanks!
>> -Joe
>> _______________________________________________
>> U-Boot mailing list
>> U-Boot@lists.denx.de
>> https://lists.denx.de/listinfo/u-boot
> 

Hi Joe, Tom,

It sounds like what Joe pointed to (my patch) has a high chance of 
causing link failure.
If the board is relying on RX delays in the Atheros PHY to ensure 
correct RGMII timing budget, then for sure it was working before and now 
it is broken. In that case, it was working by mistake; the DT blob is 
broken and should be corrected.
Sorry for the trouble this has caused.

Regards,
-Vladimir

Tom Rini May 8, 2019, 10:42 p.m. UTC | #4

On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> > On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> >>
> >> Hi Tom,
> >>
> >> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> >>
> >> I rebased on your master and built for BB Black. DHCP seems to work fine.
> >> MLO also now fits again.
> >>
> >>    Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> >>
> >> are available in the git repository at:
> >>
> >>    git://git.denx.de/u-boot-net.git master
> >>
> >> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> >>
> >>    net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> >>
> >> ----------------------------------------------------------------
> >> Carlo Caione (4):
> >>        net: phy: Add generic helpers to access MMD PHY registers
> >>        net: phy: ti: use generic helpers to access MMD registers
> >>        cmd: mdio: Switch to generic helpers when accessing the registers
> >>        net: phy: realtek: Introduce quirk to mark RXC not stoppable
> >>
> >> James Byrne (2):
> >>        net: phy: micrel: Use correct skew values on KSZ9021
> >>        net: phy: micrel: Find Micrel PHY node correctly
> >>
> >> Murali Karicheri (2):
> >>        ARM: k2g-gp-evm: update to rgmii pinmux configuration
> >>        ARM: k2g-ice: Add pinmux support for rgmii interface
> >>
> >> Pankaj Bansal (1):
> >>        drivers: net: ldpaa_eth: fix resource leak
> >>
> >> Siva Durga Prasad Paladugu (2):
> >>        net: phy: Reloc next and prev pointers inside phy_drivers
> >>        net: phy: Fix return value check phy_probe
> >>
> >> Valentin-catalin Neacsu (1):
> >>        net: phy: aquantia: Set only autoneg on in register 4.c441
> >>
> >> Vladimir Oltean (6):
> >>        net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> >>        net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> >>        net: phy: ar803x: Use common functions for RGMII internal delays
> >>        net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> >>        net: phy: ar803x: Explicitly disable RGMII delays
> > 
> > Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> > BB Black because it uses an SMSC phy, where as this evm uses an
> > AR8031/AR8033.
> > 
> > Is it possible the device tree [2] is wrong for the board? It lists
> > 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> > delay is now being disabled.
> > 
> > Any thoughts, Vladimir?
> > 
> > Thanks,
> > -Joe
> > 
> > [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> > [2] arch/arm/dts/am335x-evm.dts
> > 
> >>        net: phy: ar803x: Clarify the intention of ar8021_config
> >>
> >>   arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> >>   arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> >>   arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> >>   arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> >>   arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> >>   arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> >>   arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> >>   board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> >>   cmd/mdio.c                                      |  27 +++--
> >>   doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> >>   drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> >>   drivers/net/phy/Kconfig                         |  41 ++++++++
> >>   drivers/net/phy/aquantia.c                      |   7 +-
> >>   drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> >>   drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> >>   drivers/net/phy/phy.c                           |  21 +++-
> >>   drivers/net/phy/realtek.c                       |  19 ++++
> >>   drivers/net/phy/ti.c                            | 130 +++++-------------------
> >>   include/phy.h                                   |  70 +++++++++++++
> >>   19 files changed, 394 insertions(+), 221 deletions(-)
> >>
> >> Thanks!
> >> -Joe
> >> _______________________________________________
> >> U-Boot mailing list
> >> U-Boot@lists.denx.de
> >> https://lists.denx.de/listinfo/u-boot
> > 
> 
> Hi Joe, Tom,
> 
> It sounds like what Joe pointed to (my patch) has a high chance of 
> causing link failure.
> If the board is relying on RX delays in the Atheros PHY to ensure 
> correct RGMII timing budget, then for sure it was working before and now 
> it is broken. In that case, it was working by mistake; the DT blob is 
> broken and should be corrected.
> Sorry for the trouble this has caused.

How is this handled in the Linux kernel and/or why doesn't it fail
there?

Vladimir Oltean May 8, 2019, 10:45 p.m. UTC | #5

On 5/9/19 1:42 AM, Tom Rini wrote:
> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>>>>
>>>> Hi Tom,
>>>>
>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
>>>>
>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
>>>> MLO also now fits again.
>>>>
>>>>     Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
>>>>
>>>> are available in the git repository at:
>>>>
>>>>     git://git.denx.de/u-boot-net.git master
>>>>
>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
>>>>
>>>>     net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
>>>>
>>>> ----------------------------------------------------------------
>>>> Carlo Caione (4):
>>>>         net: phy: Add generic helpers to access MMD PHY registers
>>>>         net: phy: ti: use generic helpers to access MMD registers
>>>>         cmd: mdio: Switch to generic helpers when accessing the registers
>>>>         net: phy: realtek: Introduce quirk to mark RXC not stoppable
>>>>
>>>> James Byrne (2):
>>>>         net: phy: micrel: Use correct skew values on KSZ9021
>>>>         net: phy: micrel: Find Micrel PHY node correctly
>>>>
>>>> Murali Karicheri (2):
>>>>         ARM: k2g-gp-evm: update to rgmii pinmux configuration
>>>>         ARM: k2g-ice: Add pinmux support for rgmii interface
>>>>
>>>> Pankaj Bansal (1):
>>>>         drivers: net: ldpaa_eth: fix resource leak
>>>>
>>>> Siva Durga Prasad Paladugu (2):
>>>>         net: phy: Reloc next and prev pointers inside phy_drivers
>>>>         net: phy: Fix return value check phy_probe
>>>>
>>>> Valentin-catalin Neacsu (1):
>>>>         net: phy: aquantia: Set only autoneg on in register 4.c441
>>>>
>>>> Vladimir Oltean (6):
>>>>         net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
>>>>         net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
>>>>         net: phy: ar803x: Use common functions for RGMII internal delays
>>>>         net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
>>>>         net: phy: ar803x: Explicitly disable RGMII delays
>>>
>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
>>> BB Black because it uses an SMSC phy, where as this evm uses an
>>> AR8031/AR8033.
>>>
>>> Is it possible the device tree [2] is wrong for the board? It lists
>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
>>> delay is now being disabled.
>>>
>>> Any thoughts, Vladimir?
>>>
>>> Thanks,
>>> -Joe
>>>
>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
>>> [2] arch/arm/dts/am335x-evm.dts
>>>
>>>>         net: phy: ar803x: Clarify the intention of ar8021_config
>>>>
>>>>    arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
>>>>    arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
>>>>    arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
>>>>    arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
>>>>    arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
>>>>    arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
>>>>    arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
>>>>    board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
>>>>    cmd/mdio.c                                      |  27 +++--
>>>>    doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
>>>>    drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
>>>>    drivers/net/phy/Kconfig                         |  41 ++++++++
>>>>    drivers/net/phy/aquantia.c                      |   7 +-
>>>>    drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
>>>>    drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
>>>>    drivers/net/phy/phy.c                           |  21 +++-
>>>>    drivers/net/phy/realtek.c                       |  19 ++++
>>>>    drivers/net/phy/ti.c                            | 130 +++++-------------------
>>>>    include/phy.h                                   |  70 +++++++++++++
>>>>    19 files changed, 394 insertions(+), 221 deletions(-)
>>>>
>>>> Thanks!
>>>> -Joe
>>>> _______________________________________________
>>>> U-Boot mailing list
>>>> U-Boot@lists.denx.de
>>>> https://lists.denx.de/listinfo/u-boot
>>>
>>
>> Hi Joe, Tom,
>>
>> It sounds like what Joe pointed to (my patch) has a high chance of
>> causing link failure.
>> If the board is relying on RX delays in the Atheros PHY to ensure
>> correct RGMII timing budget, then for sure it was working before and now
>> it is broken. In that case, it was working by mistake; the DT blob is
>> broken and should be corrected.
>> Sorry for the trouble this has caused.
> 
> How is this handled in the Linux kernel and/or why doesn't it fail
> there?
> 

On the latest net-next, it's handled the same: disable everything and 
enable only what's specified in phy-mode. I didn't keep track of older 
versions.

-Vladimir

Tom Rini May 8, 2019, 10:48 p.m. UTC | #6

On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> On 5/9/19 1:42 AM, Tom Rini wrote:
> > On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> >> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> >>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> >>>>
> >>>> Hi Tom,
> >>>>
> >>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> >>>>
> >>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> >>>> MLO also now fits again.
> >>>>
> >>>>     Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> >>>>
> >>>> are available in the git repository at:
> >>>>
> >>>>     git://git.denx.de/u-boot-net.git master
> >>>>
> >>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> >>>>
> >>>>     net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> >>>>
> >>>> ----------------------------------------------------------------
> >>>> Carlo Caione (4):
> >>>>         net: phy: Add generic helpers to access MMD PHY registers
> >>>>         net: phy: ti: use generic helpers to access MMD registers
> >>>>         cmd: mdio: Switch to generic helpers when accessing the registers
> >>>>         net: phy: realtek: Introduce quirk to mark RXC not stoppable
> >>>>
> >>>> James Byrne (2):
> >>>>         net: phy: micrel: Use correct skew values on KSZ9021
> >>>>         net: phy: micrel: Find Micrel PHY node correctly
> >>>>
> >>>> Murali Karicheri (2):
> >>>>         ARM: k2g-gp-evm: update to rgmii pinmux configuration
> >>>>         ARM: k2g-ice: Add pinmux support for rgmii interface
> >>>>
> >>>> Pankaj Bansal (1):
> >>>>         drivers: net: ldpaa_eth: fix resource leak
> >>>>
> >>>> Siva Durga Prasad Paladugu (2):
> >>>>         net: phy: Reloc next and prev pointers inside phy_drivers
> >>>>         net: phy: Fix return value check phy_probe
> >>>>
> >>>> Valentin-catalin Neacsu (1):
> >>>>         net: phy: aquantia: Set only autoneg on in register 4.c441
> >>>>
> >>>> Vladimir Oltean (6):
> >>>>         net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> >>>>         net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> >>>>         net: phy: ar803x: Use common functions for RGMII internal delays
> >>>>         net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> >>>>         net: phy: ar803x: Explicitly disable RGMII delays
> >>>
> >>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> >>> BB Black because it uses an SMSC phy, where as this evm uses an
> >>> AR8031/AR8033.
> >>>
> >>> Is it possible the device tree [2] is wrong for the board? It lists
> >>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> >>> delay is now being disabled.
> >>>
> >>> Any thoughts, Vladimir?
> >>>
> >>> Thanks,
> >>> -Joe
> >>>
> >>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> >>> [2] arch/arm/dts/am335x-evm.dts
> >>>
> >>>>         net: phy: ar803x: Clarify the intention of ar8021_config
> >>>>
> >>>>    arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> >>>>    arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> >>>>    arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> >>>>    arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> >>>>    arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> >>>>    arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> >>>>    arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> >>>>    board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> >>>>    cmd/mdio.c                                      |  27 +++--
> >>>>    doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> >>>>    drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> >>>>    drivers/net/phy/Kconfig                         |  41 ++++++++
> >>>>    drivers/net/phy/aquantia.c                      |   7 +-
> >>>>    drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> >>>>    drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> >>>>    drivers/net/phy/phy.c                           |  21 +++-
> >>>>    drivers/net/phy/realtek.c                       |  19 ++++
> >>>>    drivers/net/phy/ti.c                            | 130 +++++-------------------
> >>>>    include/phy.h                                   |  70 +++++++++++++
> >>>>    19 files changed, 394 insertions(+), 221 deletions(-)
> >>>>
> >>>> Thanks!
> >>>> -Joe
> >>>> _______________________________________________
> >>>> U-Boot mailing list
> >>>> U-Boot@lists.denx.de
> >>>> https://lists.denx.de/listinfo/u-boot
> >>>
> >>
> >> Hi Joe, Tom,
> >>
> >> It sounds like what Joe pointed to (my patch) has a high chance of
> >> causing link failure.
> >> If the board is relying on RX delays in the Atheros PHY to ensure
> >> correct RGMII timing budget, then for sure it was working before and now
> >> it is broken. In that case, it was working by mistake; the DT blob is
> >> broken and should be corrected.
> >> Sorry for the trouble this has caused.
> > 
> > How is this handled in the Linux kernel and/or why doesn't it fail
> > there?
> 
> On the latest net-next, it's handled the same: disable everything and 
> enable only what's specified in phy-mode. I didn't keep track of older 
> versions.

So you would expect the network to be broken on net-next with this DTS?
Because that's not allowed...

Vladimir Oltean May 8, 2019, 10:52 p.m. UTC | #7

On 5/9/19 1:48 AM, Tom Rini wrote:
> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
>> On 5/9/19 1:42 AM, Tom Rini wrote:
>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>>>>>>
>>>>>> Hi Tom,
>>>>>>
>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
>>>>>>
>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
>>>>>> MLO also now fits again.
>>>>>>
>>>>>>      Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
>>>>>>
>>>>>> are available in the git repository at:
>>>>>>
>>>>>>      git://git.denx.de/u-boot-net.git master
>>>>>>
>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
>>>>>>
>>>>>>      net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
>>>>>>
>>>>>> ----------------------------------------------------------------
>>>>>> Carlo Caione (4):
>>>>>>          net: phy: Add generic helpers to access MMD PHY registers
>>>>>>          net: phy: ti: use generic helpers to access MMD registers
>>>>>>          cmd: mdio: Switch to generic helpers when accessing the registers
>>>>>>          net: phy: realtek: Introduce quirk to mark RXC not stoppable
>>>>>>
>>>>>> James Byrne (2):
>>>>>>          net: phy: micrel: Use correct skew values on KSZ9021
>>>>>>          net: phy: micrel: Find Micrel PHY node correctly
>>>>>>
>>>>>> Murali Karicheri (2):
>>>>>>          ARM: k2g-gp-evm: update to rgmii pinmux configuration
>>>>>>          ARM: k2g-ice: Add pinmux support for rgmii interface
>>>>>>
>>>>>> Pankaj Bansal (1):
>>>>>>          drivers: net: ldpaa_eth: fix resource leak
>>>>>>
>>>>>> Siva Durga Prasad Paladugu (2):
>>>>>>          net: phy: Reloc next and prev pointers inside phy_drivers
>>>>>>          net: phy: Fix return value check phy_probe
>>>>>>
>>>>>> Valentin-catalin Neacsu (1):
>>>>>>          net: phy: aquantia: Set only autoneg on in register 4.c441
>>>>>>
>>>>>> Vladimir Oltean (6):
>>>>>>          net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
>>>>>>          net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
>>>>>>          net: phy: ar803x: Use common functions for RGMII internal delays
>>>>>>          net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
>>>>>>          net: phy: ar803x: Explicitly disable RGMII delays
>>>>>
>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
>>>>> AR8031/AR8033.
>>>>>
>>>>> Is it possible the device tree [2] is wrong for the board? It lists
>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
>>>>> delay is now being disabled.
>>>>>
>>>>> Any thoughts, Vladimir?
>>>>>
>>>>> Thanks,
>>>>> -Joe
>>>>>
>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
>>>>> [2] arch/arm/dts/am335x-evm.dts
>>>>>
>>>>>>          net: phy: ar803x: Clarify the intention of ar8021_config
>>>>>>
>>>>>>     arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
>>>>>>     arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
>>>>>>     arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
>>>>>>     arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
>>>>>>     arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
>>>>>>     arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
>>>>>>     arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
>>>>>>     board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
>>>>>>     cmd/mdio.c                                      |  27 +++--
>>>>>>     doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
>>>>>>     drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
>>>>>>     drivers/net/phy/Kconfig                         |  41 ++++++++
>>>>>>     drivers/net/phy/aquantia.c                      |   7 +-
>>>>>>     drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
>>>>>>     drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
>>>>>>     drivers/net/phy/phy.c                           |  21 +++-
>>>>>>     drivers/net/phy/realtek.c                       |  19 ++++
>>>>>>     drivers/net/phy/ti.c                            | 130 +++++-------------------
>>>>>>     include/phy.h                                   |  70 +++++++++++++
>>>>>>     19 files changed, 394 insertions(+), 221 deletions(-)
>>>>>>
>>>>>> Thanks!
>>>>>> -Joe
>>>>>> _______________________________________________
>>>>>> U-Boot mailing list
>>>>>> U-Boot@lists.denx.de
>>>>>> https://lists.denx.de/listinfo/u-boot
>>>>>
>>>>
>>>> Hi Joe, Tom,
>>>>
>>>> It sounds like what Joe pointed to (my patch) has a high chance of
>>>> causing link failure.
>>>> If the board is relying on RX delays in the Atheros PHY to ensure
>>>> correct RGMII timing budget, then for sure it was working before and now
>>>> it is broken. In that case, it was working by mistake; the DT blob is
>>>> broken and should be corrected.
>>>> Sorry for the trouble this has caused.
>>>
>>> How is this handled in the Linux kernel and/or why doesn't it fail
>>> there?
>>
>> On the latest net-next, it's handled the same: disable everything and
>> enable only what's specified in phy-mode. I didn't keep track of older
>> versions.
> 
> So you would expect the network to be broken on net-next with this DTS?
> Because that's not allowed...
> 

Yes, if it's the same problem, the behavior should be the same.
I see net-next is only rejecting the bad DT since 2019-02-21:
https://patchwork.kernel.org/patch/10819279/
So it depends when you checked it last time.

-Vladimir

Tom Rini May 8, 2019, 10:54 p.m. UTC | #8

On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
> On 5/9/19 1:48 AM, Tom Rini wrote:
> > On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> >> On 5/9/19 1:42 AM, Tom Rini wrote:
> >>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> >>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> >>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> >>>>>>
> >>>>>> Hi Tom,
> >>>>>>
> >>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> >>>>>>
> >>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> >>>>>> MLO also now fits again.
> >>>>>>
> >>>>>>      Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> >>>>>>
> >>>>>> are available in the git repository at:
> >>>>>>
> >>>>>>      git://git.denx.de/u-boot-net.git master
> >>>>>>
> >>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> >>>>>>
> >>>>>>      net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> >>>>>>
> >>>>>> ----------------------------------------------------------------
> >>>>>> Carlo Caione (4):
> >>>>>>          net: phy: Add generic helpers to access MMD PHY registers
> >>>>>>          net: phy: ti: use generic helpers to access MMD registers
> >>>>>>          cmd: mdio: Switch to generic helpers when accessing the registers
> >>>>>>          net: phy: realtek: Introduce quirk to mark RXC not stoppable
> >>>>>>
> >>>>>> James Byrne (2):
> >>>>>>          net: phy: micrel: Use correct skew values on KSZ9021
> >>>>>>          net: phy: micrel: Find Micrel PHY node correctly
> >>>>>>
> >>>>>> Murali Karicheri (2):
> >>>>>>          ARM: k2g-gp-evm: update to rgmii pinmux configuration
> >>>>>>          ARM: k2g-ice: Add pinmux support for rgmii interface
> >>>>>>
> >>>>>> Pankaj Bansal (1):
> >>>>>>          drivers: net: ldpaa_eth: fix resource leak
> >>>>>>
> >>>>>> Siva Durga Prasad Paladugu (2):
> >>>>>>          net: phy: Reloc next and prev pointers inside phy_drivers
> >>>>>>          net: phy: Fix return value check phy_probe
> >>>>>>
> >>>>>> Valentin-catalin Neacsu (1):
> >>>>>>          net: phy: aquantia: Set only autoneg on in register 4.c441
> >>>>>>
> >>>>>> Vladimir Oltean (6):
> >>>>>>          net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> >>>>>>          net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> >>>>>>          net: phy: ar803x: Use common functions for RGMII internal delays
> >>>>>>          net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> >>>>>>          net: phy: ar803x: Explicitly disable RGMII delays
> >>>>>
> >>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> >>>>> BB Black because it uses an SMSC phy, where as this evm uses an
> >>>>> AR8031/AR8033.
> >>>>>
> >>>>> Is it possible the device tree [2] is wrong for the board? It lists
> >>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> >>>>> delay is now being disabled.
> >>>>>
> >>>>> Any thoughts, Vladimir?
> >>>>>
> >>>>> Thanks,
> >>>>> -Joe
> >>>>>
> >>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> >>>>> [2] arch/arm/dts/am335x-evm.dts
> >>>>>
> >>>>>>          net: phy: ar803x: Clarify the intention of ar8021_config
> >>>>>>
> >>>>>>     arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> >>>>>>     arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> >>>>>>     arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> >>>>>>     arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> >>>>>>     arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> >>>>>>     arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> >>>>>>     arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> >>>>>>     board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> >>>>>>     cmd/mdio.c                                      |  27 +++--
> >>>>>>     doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> >>>>>>     drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> >>>>>>     drivers/net/phy/Kconfig                         |  41 ++++++++
> >>>>>>     drivers/net/phy/aquantia.c                      |   7 +-
> >>>>>>     drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> >>>>>>     drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> >>>>>>     drivers/net/phy/phy.c                           |  21 +++-
> >>>>>>     drivers/net/phy/realtek.c                       |  19 ++++
> >>>>>>     drivers/net/phy/ti.c                            | 130 +++++-------------------
> >>>>>>     include/phy.h                                   |  70 +++++++++++++
> >>>>>>     19 files changed, 394 insertions(+), 221 deletions(-)
> >>>>>>
> >>>>>> Thanks!
> >>>>>> -Joe
> >>>>>> _______________________________________________
> >>>>>> U-Boot mailing list
> >>>>>> U-Boot@lists.denx.de
> >>>>>> https://lists.denx.de/listinfo/u-boot
> >>>>>
> >>>>
> >>>> Hi Joe, Tom,
> >>>>
> >>>> It sounds like what Joe pointed to (my patch) has a high chance of
> >>>> causing link failure.
> >>>> If the board is relying on RX delays in the Atheros PHY to ensure
> >>>> correct RGMII timing budget, then for sure it was working before and now
> >>>> it is broken. In that case, it was working by mistake; the DT blob is
> >>>> broken and should be corrected.
> >>>> Sorry for the trouble this has caused.
> >>>
> >>> How is this handled in the Linux kernel and/or why doesn't it fail
> >>> there?
> >>
> >> On the latest net-next, it's handled the same: disable everything and
> >> enable only what's specified in phy-mode. I didn't keep track of older
> >> versions.
> > 
> > So you would expect the network to be broken on net-next with this DTS?
> > Because that's not allowed...
> > 
> 
> Yes, if it's the same problem, the behavior should be the same.
> I see net-next is only rejecting the bad DT since 2019-02-21:
> https://patchwork.kernel.org/patch/10819279/
> So it depends when you checked it last time.

I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
there some work-around for the DTS so that ethernet works?  You cannot
break existing DTs.

Vladimir Oltean May 8, 2019, 11:05 p.m. UTC | #9

On 5/9/19 1:55 AM, Tom Rini wrote:
> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
>> On 5/9/19 1:48 AM, Tom Rini wrote:
>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>>>>>>>>
>>>>>>>> Hi Tom,
>>>>>>>>
>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
>>>>>>>>
>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
>>>>>>>> MLO also now fits again.
>>>>>>>>
>>>>>>>>       Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
>>>>>>>>
>>>>>>>> are available in the git repository at:
>>>>>>>>
>>>>>>>>       git://git.denx.de/u-boot-net.git master
>>>>>>>>
>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
>>>>>>>>
>>>>>>>>       net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
>>>>>>>>
>>>>>>>> ----------------------------------------------------------------
>>>>>>>> Carlo Caione (4):
>>>>>>>>           net: phy: Add generic helpers to access MMD PHY registers
>>>>>>>>           net: phy: ti: use generic helpers to access MMD registers
>>>>>>>>           cmd: mdio: Switch to generic helpers when accessing the registers
>>>>>>>>           net: phy: realtek: Introduce quirk to mark RXC not stoppable
>>>>>>>>
>>>>>>>> James Byrne (2):
>>>>>>>>           net: phy: micrel: Use correct skew values on KSZ9021
>>>>>>>>           net: phy: micrel: Find Micrel PHY node correctly
>>>>>>>>
>>>>>>>> Murali Karicheri (2):
>>>>>>>>           ARM: k2g-gp-evm: update to rgmii pinmux configuration
>>>>>>>>           ARM: k2g-ice: Add pinmux support for rgmii interface
>>>>>>>>
>>>>>>>> Pankaj Bansal (1):
>>>>>>>>           drivers: net: ldpaa_eth: fix resource leak
>>>>>>>>
>>>>>>>> Siva Durga Prasad Paladugu (2):
>>>>>>>>           net: phy: Reloc next and prev pointers inside phy_drivers
>>>>>>>>           net: phy: Fix return value check phy_probe
>>>>>>>>
>>>>>>>> Valentin-catalin Neacsu (1):
>>>>>>>>           net: phy: aquantia: Set only autoneg on in register 4.c441
>>>>>>>>
>>>>>>>> Vladimir Oltean (6):
>>>>>>>>           net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
>>>>>>>>           net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
>>>>>>>>           net: phy: ar803x: Use common functions for RGMII internal delays
>>>>>>>>           net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
>>>>>>>>           net: phy: ar803x: Explicitly disable RGMII delays
>>>>>>>
>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
>>>>>>> AR8031/AR8033.
>>>>>>>
>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
>>>>>>> delay is now being disabled.
>>>>>>>
>>>>>>> Any thoughts, Vladimir?
>>>>>>>
>>>>>>> Thanks,
>>>>>>> -Joe
>>>>>>>
>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
>>>>>>> [2] arch/arm/dts/am335x-evm.dts
>>>>>>>
>>>>>>>>           net: phy: ar803x: Clarify the intention of ar8021_config
>>>>>>>>
>>>>>>>>      arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
>>>>>>>>      arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
>>>>>>>>      arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
>>>>>>>>      arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
>>>>>>>>      arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
>>>>>>>>      arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
>>>>>>>>      arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
>>>>>>>>      board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
>>>>>>>>      cmd/mdio.c                                      |  27 +++--
>>>>>>>>      doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
>>>>>>>>      drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
>>>>>>>>      drivers/net/phy/Kconfig                         |  41 ++++++++
>>>>>>>>      drivers/net/phy/aquantia.c                      |   7 +-
>>>>>>>>      drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
>>>>>>>>      drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
>>>>>>>>      drivers/net/phy/phy.c                           |  21 +++-
>>>>>>>>      drivers/net/phy/realtek.c                       |  19 ++++
>>>>>>>>      drivers/net/phy/ti.c                            | 130 +++++-------------------
>>>>>>>>      include/phy.h                                   |  70 +++++++++++++
>>>>>>>>      19 files changed, 394 insertions(+), 221 deletions(-)
>>>>>>>>
>>>>>>>> Thanks!
>>>>>>>> -Joe
>>>>>>>> _______________________________________________
>>>>>>>> U-Boot mailing list
>>>>>>>> U-Boot@lists.denx.de
>>>>>>>> https://lists.denx.de/listinfo/u-boot
>>>>>>>
>>>>>>
>>>>>> Hi Joe, Tom,
>>>>>>
>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
>>>>>> causing link failure.
>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
>>>>>> correct RGMII timing budget, then for sure it was working before and now
>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
>>>>>> broken and should be corrected.
>>>>>> Sorry for the trouble this has caused.
>>>>>
>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
>>>>> there?
>>>>
>>>> On the latest net-next, it's handled the same: disable everything and
>>>> enable only what's specified in phy-mode. I didn't keep track of older
>>>> versions.
>>>
>>> So you would expect the network to be broken on net-next with this DTS?
>>> Because that's not allowed...
>>>
>>
>> Yes, if it's the same problem, the behavior should be the same.
>> I see net-next is only rejecting the bad DT since 2019-02-21:
>> https://patchwork.kernel.org/patch/10819279/
>> So it depends when you checked it last time.
> 
> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
> there some work-around for the DTS so that ethernet works?

Work-around in Linux or in U-boot?
U-boot can fix up the DT for Linux and replace "rgmii-txid" with 
"rgmii-id", whereas neither Linux nor U-boot can do anything for 
themselves except either load a correct DT blob, or not use (revert, not 
upgrade to, etc) the enforcing patch.

> You cannot break existing DTs
RGMII delay breakages happen all the time. To play the devil's advocate, 
protecting against them should be done by observing the semantics 
described in the devicetree/bindings document.
If you follow Linux net-next, a breakage for RTL8211F is planned out 
right as we speak.

But let's wait until we know for sure that this is what's causing the 
issues.

Regards,
-Vladimir

Tom Rini May 9, 2019, 2:38 a.m. UTC | #10

+ Rob

On Wed, May 08, 2019 at 11:05:29PM +0000, Vladimir Oltean wrote:
> On 5/9/19 1:55 AM, Tom Rini wrote:
> > On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
> >> On 5/9/19 1:48 AM, Tom Rini wrote:
> >>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> >>>> On 5/9/19 1:42 AM, Tom Rini wrote:
> >>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> >>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> >>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> >>>>>>>>
> >>>>>>>> Hi Tom,
> >>>>>>>>
> >>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> >>>>>>>>
> >>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> >>>>>>>> MLO also now fits again.
> >>>>>>>>
> >>>>>>>>       Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> >>>>>>>>
> >>>>>>>> are available in the git repository at:
> >>>>>>>>
> >>>>>>>>       git://git.denx.de/u-boot-net.git master
> >>>>>>>>
> >>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> >>>>>>>>
> >>>>>>>>       net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> >>>>>>>>
> >>>>>>>> ----------------------------------------------------------------
> >>>>>>>> Carlo Caione (4):
> >>>>>>>>           net: phy: Add generic helpers to access MMD PHY registers
> >>>>>>>>           net: phy: ti: use generic helpers to access MMD registers
> >>>>>>>>           cmd: mdio: Switch to generic helpers when accessing the registers
> >>>>>>>>           net: phy: realtek: Introduce quirk to mark RXC not stoppable
> >>>>>>>>
> >>>>>>>> James Byrne (2):
> >>>>>>>>           net: phy: micrel: Use correct skew values on KSZ9021
> >>>>>>>>           net: phy: micrel: Find Micrel PHY node correctly
> >>>>>>>>
> >>>>>>>> Murali Karicheri (2):
> >>>>>>>>           ARM: k2g-gp-evm: update to rgmii pinmux configuration
> >>>>>>>>           ARM: k2g-ice: Add pinmux support for rgmii interface
> >>>>>>>>
> >>>>>>>> Pankaj Bansal (1):
> >>>>>>>>           drivers: net: ldpaa_eth: fix resource leak
> >>>>>>>>
> >>>>>>>> Siva Durga Prasad Paladugu (2):
> >>>>>>>>           net: phy: Reloc next and prev pointers inside phy_drivers
> >>>>>>>>           net: phy: Fix return value check phy_probe
> >>>>>>>>
> >>>>>>>> Valentin-catalin Neacsu (1):
> >>>>>>>>           net: phy: aquantia: Set only autoneg on in register 4.c441
> >>>>>>>>
> >>>>>>>> Vladimir Oltean (6):
> >>>>>>>>           net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> >>>>>>>>           net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> >>>>>>>>           net: phy: ar803x: Use common functions for RGMII internal delays
> >>>>>>>>           net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> >>>>>>>>           net: phy: ar803x: Explicitly disable RGMII delays
> >>>>>>>
> >>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> >>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
> >>>>>>> AR8031/AR8033.
> >>>>>>>
> >>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
> >>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> >>>>>>> delay is now being disabled.
> >>>>>>>
> >>>>>>> Any thoughts, Vladimir?
> >>>>>>>
> >>>>>>> Thanks,
> >>>>>>> -Joe
> >>>>>>>
> >>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> >>>>>>> [2] arch/arm/dts/am335x-evm.dts
> >>>>>>>
> >>>>>>>>           net: phy: ar803x: Clarify the intention of ar8021_config
> >>>>>>>>
> >>>>>>>>      arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> >>>>>>>>      arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> >>>>>>>>      arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> >>>>>>>>      arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> >>>>>>>>      arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> >>>>>>>>      arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> >>>>>>>>      arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> >>>>>>>>      board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> >>>>>>>>      cmd/mdio.c                                      |  27 +++--
> >>>>>>>>      doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> >>>>>>>>      drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> >>>>>>>>      drivers/net/phy/Kconfig                         |  41 ++++++++
> >>>>>>>>      drivers/net/phy/aquantia.c                      |   7 +-
> >>>>>>>>      drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> >>>>>>>>      drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> >>>>>>>>      drivers/net/phy/phy.c                           |  21 +++-
> >>>>>>>>      drivers/net/phy/realtek.c                       |  19 ++++
> >>>>>>>>      drivers/net/phy/ti.c                            | 130 +++++-------------------
> >>>>>>>>      include/phy.h                                   |  70 +++++++++++++
> >>>>>>>>      19 files changed, 394 insertions(+), 221 deletions(-)
> >>>>>>>>
> >>>>>>>> Thanks!
> >>>>>>>> -Joe
> >>>>>>>> _______________________________________________
> >>>>>>>> U-Boot mailing list
> >>>>>>>> U-Boot@lists.denx.de
> >>>>>>>> https://lists.denx.de/listinfo/u-boot
> >>>>>>>
> >>>>>>
> >>>>>> Hi Joe, Tom,
> >>>>>>
> >>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
> >>>>>> causing link failure.
> >>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
> >>>>>> correct RGMII timing budget, then for sure it was working before and now
> >>>>>> it is broken. In that case, it was working by mistake; the DT blob is
> >>>>>> broken and should be corrected.
> >>>>>> Sorry for the trouble this has caused.
> >>>>>
> >>>>> How is this handled in the Linux kernel and/or why doesn't it fail
> >>>>> there?
> >>>>
> >>>> On the latest net-next, it's handled the same: disable everything and
> >>>> enable only what's specified in phy-mode. I didn't keep track of older
> >>>> versions.
> >>>
> >>> So you would expect the network to be broken on net-next with this DTS?
> >>> Because that's not allowed...
> >>>
> >>
> >> Yes, if it's the same problem, the behavior should be the same.
> >> I see net-next is only rejecting the bad DT since 2019-02-21:
> >> https://patchwork.kernel.org/patch/10819279/
> >> So it depends when you checked it last time.
> > 
> > I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
> > there some work-around for the DTS so that ethernet works?
> 
> Work-around in Linux or in U-boot?
> U-boot can fix up the DT for Linux and replace "rgmii-txid" with 
> "rgmii-id", whereas neither Linux nor U-boot can do anything for 
> themselves except either load a correct DT blob, or not use (revert, not 
> upgrade to, etc) the enforcing patch.
> 
> > You cannot break existing DTs
> RGMII delay breakages happen all the time. To play the devil's advocate, 
> protecting against them should be done by observing the semantics 
> described in the devicetree/bindings document.
> If you follow Linux net-next, a breakage for RTL8211F is planned out 
> right as we speak.
> 
> But let's wait until we know for sure that this is what's causing the 
> issues.

OK, so net-next works.  Looking harder that's because of:
commit 37685f6a63eeca2135d1f704e7638409a071b1f6
Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
Date:   Tue Feb 19 08:46:33 2019 -0800

    ARM: dts: am335x-evm: Fix PHY mode for ethernet

which changes:
 &cpsw_emac0 {
        phy-handle = <&ethphy0>;
-       phy-mode = "rgmii-txid";
+       phy-mode = "rgmii-id";
 };


Which explains why things work but I still cannot believe that despite
"DT is ABI" and "You cannot break existing DT binaries" we're apparently
breaking existing DT binaries.

Vladimir Oltean May 9, 2019, 12:51 p.m. UTC | #11

On 09.05.2019 02:05, Vladimir Oltean wrote:
> On 5/9/19 1:55 AM, Tom Rini wrote:
>> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
>>> On 5/9/19 1:48 AM, Tom Rini wrote:
>>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
>>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
>>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
>>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
>>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>>>>>>>>>
>>>>>>>>> Hi Tom,
>>>>>>>>>
>>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
>>>>>>>>>
>>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
>>>>>>>>> MLO also now fits again.
>>>>>>>>>
>>>>>>>>>        Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
>>>>>>>>>
>>>>>>>>> are available in the git repository at:
>>>>>>>>>
>>>>>>>>>        git://git.denx.de/u-boot-net.git master
>>>>>>>>>
>>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
>>>>>>>>>
>>>>>>>>>        net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
>>>>>>>>>
>>>>>>>>> ----------------------------------------------------------------
>>>>>>>>> Carlo Caione (4):
>>>>>>>>>            net: phy: Add generic helpers to access MMD PHY registers
>>>>>>>>>            net: phy: ti: use generic helpers to access MMD registers
>>>>>>>>>            cmd: mdio: Switch to generic helpers when accessing the registers
>>>>>>>>>            net: phy: realtek: Introduce quirk to mark RXC not stoppable
>>>>>>>>>
>>>>>>>>> James Byrne (2):
>>>>>>>>>            net: phy: micrel: Use correct skew values on KSZ9021
>>>>>>>>>            net: phy: micrel: Find Micrel PHY node correctly
>>>>>>>>>
>>>>>>>>> Murali Karicheri (2):
>>>>>>>>>            ARM: k2g-gp-evm: update to rgmii pinmux configuration
>>>>>>>>>            ARM: k2g-ice: Add pinmux support for rgmii interface
>>>>>>>>>
>>>>>>>>> Pankaj Bansal (1):
>>>>>>>>>            drivers: net: ldpaa_eth: fix resource leak
>>>>>>>>>
>>>>>>>>> Siva Durga Prasad Paladugu (2):
>>>>>>>>>            net: phy: Reloc next and prev pointers inside phy_drivers
>>>>>>>>>            net: phy: Fix return value check phy_probe
>>>>>>>>>
>>>>>>>>> Valentin-catalin Neacsu (1):
>>>>>>>>>            net: phy: aquantia: Set only autoneg on in register 4.c441
>>>>>>>>>
>>>>>>>>> Vladimir Oltean (6):
>>>>>>>>>            net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
>>>>>>>>>            net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
>>>>>>>>>            net: phy: ar803x: Use common functions for RGMII internal delays
>>>>>>>>>            net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
>>>>>>>>>            net: phy: ar803x: Explicitly disable RGMII delays
>>>>>>>>
>>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
>>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
>>>>>>>> AR8031/AR8033.
>>>>>>>>
>>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
>>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
>>>>>>>> delay is now being disabled.
>>>>>>>>
>>>>>>>> Any thoughts, Vladimir?
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> -Joe
>>>>>>>>
>>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
>>>>>>>> [2] arch/arm/dts/am335x-evm.dts
>>>>>>>>
>>>>>>>>>            net: phy: ar803x: Clarify the intention of ar8021_config
>>>>>>>>>
>>>>>>>>>       arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
>>>>>>>>>       arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
>>>>>>>>>       arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
>>>>>>>>>       arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
>>>>>>>>>       arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
>>>>>>>>>       arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
>>>>>>>>>       arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
>>>>>>>>>       board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
>>>>>>>>>       cmd/mdio.c                                      |  27 +++--
>>>>>>>>>       doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
>>>>>>>>>       drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
>>>>>>>>>       drivers/net/phy/Kconfig                         |  41 ++++++++
>>>>>>>>>       drivers/net/phy/aquantia.c                      |   7 +-
>>>>>>>>>       drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
>>>>>>>>>       drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
>>>>>>>>>       drivers/net/phy/phy.c                           |  21 +++-
>>>>>>>>>       drivers/net/phy/realtek.c                       |  19 ++++
>>>>>>>>>       drivers/net/phy/ti.c                            | 130 +++++-------------------
>>>>>>>>>       include/phy.h                                   |  70 +++++++++++++
>>>>>>>>>       19 files changed, 394 insertions(+), 221 deletions(-)
>>>>>>>>>
>>>>>>>>> Thanks!
>>>>>>>>> -Joe
>>>>>>>>> _______________________________________________
>>>>>>>>> U-Boot mailing list
>>>>>>>>> U-Boot@lists.denx.de
>>>>>>>>> https://lists.denx.de/listinfo/u-boot
>>>>>>>>
>>>>>>>
>>>>>>> Hi Joe, Tom,
>>>>>>>
>>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
>>>>>>> causing link failure.
>>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
>>>>>>> correct RGMII timing budget, then for sure it was working before and now
>>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
>>>>>>> broken and should be corrected.
>>>>>>> Sorry for the trouble this has caused.
>>>>>>
>>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
>>>>>> there?
>>>>>
>>>>> On the latest net-next, it's handled the same: disable everything and
>>>>> enable only what's specified in phy-mode. I didn't keep track of older
>>>>> versions.
>>>>
>>>> So you would expect the network to be broken on net-next with this DTS?
>>>> Because that's not allowed...
>>>>
>>>
>>> Yes, if it's the same problem, the behavior should be the same.
>>> I see net-next is only rejecting the bad DT since 2019-02-21:
>>> https://patchwork.kernel.org/patch/10819279/
>>> So it depends when you checked it last time.
>>
>> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
>> there some work-around for the DTS so that ethernet works?
> 
> Work-around in Linux or in U-boot?
> U-boot can fix up the DT for Linux and replace "rgmii-txid" with
> "rgmii-id", whereas neither Linux nor U-boot can do anything for
> themselves except either load a correct DT blob, or not use (revert, not
> upgrade to, etc) the enforcing patch.
> 
>> You cannot break existing DTs
> RGMII delay breakages happen all the time. To play the devil's advocate,
> protecting against them should be done by observing the semantics
> described in the devicetree/bindings document.
> If you follow Linux net-next, a breakage for RTL8211F is planned out
> right as we speak.
> 
> But let's wait until we know for sure that this is what's causing the
> issues.
> 
> Regards,
> -Vladimir
> 

Hi Tom,

I understand now what you mean by "workaround".
Yes you can enable RGMII delays by hand in U-boot:

Check if RX delay is enabled (bit 15 of debug register 0):
=> mdio write eTSEC1 0x1D 0
=> mdio read eTSEC1 0x1E
=> mdio write eTSEC1 0x1E <new value>

Check if TX delay is enabled (bit 8 of debug register 5):
=> mdio write eTSEC1 0x1D 5
=> mdio read eTSEC1 0x1E
=> mdio write eTSEC1 0x1E <new value>

Replace eTSEC1 with your net device from "mdio list".

Regards,
-Vladimir

Joe Hershberger May 10, 2019, 9:50 p.m. UTC | #12

Hi Vladimir and Tom,

On Thu, May 9, 2019 at 7:51 AM Vladimir Oltean <vladimir.oltean@nxp.com> wrote:
>
> On 09.05.2019 02:05, Vladimir Oltean wrote:
> > On 5/9/19 1:55 AM, Tom Rini wrote:
> >> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
> >>> On 5/9/19 1:48 AM, Tom Rini wrote:
> >>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> >>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
> >>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> >>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> >>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> >>>>>>>>>
> >>>>>>>>> Hi Tom,
> >>>>>>>>>
> >>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> >>>>>>>>>
> >>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> >>>>>>>>> MLO also now fits again.
> >>>>>>>>>
> >>>>>>>>>        Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> >>>>>>>>>
> >>>>>>>>> are available in the git repository at:
> >>>>>>>>>
> >>>>>>>>>        git://git.denx.de/u-boot-net.git master
> >>>>>>>>>
> >>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> >>>>>>>>>
> >>>>>>>>>        net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> >>>>>>>>>
> >>>>>>>>> ----------------------------------------------------------------
> >>>>>>>>> Carlo Caione (4):
> >>>>>>>>>            net: phy: Add generic helpers to access MMD PHY registers
> >>>>>>>>>            net: phy: ti: use generic helpers to access MMD registers
> >>>>>>>>>            cmd: mdio: Switch to generic helpers when accessing the registers
> >>>>>>>>>            net: phy: realtek: Introduce quirk to mark RXC not stoppable
> >>>>>>>>>
> >>>>>>>>> James Byrne (2):
> >>>>>>>>>            net: phy: micrel: Use correct skew values on KSZ9021
> >>>>>>>>>            net: phy: micrel: Find Micrel PHY node correctly
> >>>>>>>>>
> >>>>>>>>> Murali Karicheri (2):
> >>>>>>>>>            ARM: k2g-gp-evm: update to rgmii pinmux configuration
> >>>>>>>>>            ARM: k2g-ice: Add pinmux support for rgmii interface
> >>>>>>>>>
> >>>>>>>>> Pankaj Bansal (1):
> >>>>>>>>>            drivers: net: ldpaa_eth: fix resource leak
> >>>>>>>>>
> >>>>>>>>> Siva Durga Prasad Paladugu (2):
> >>>>>>>>>            net: phy: Reloc next and prev pointers inside phy_drivers
> >>>>>>>>>            net: phy: Fix return value check phy_probe
> >>>>>>>>>
> >>>>>>>>> Valentin-catalin Neacsu (1):
> >>>>>>>>>            net: phy: aquantia: Set only autoneg on in register 4.c441
> >>>>>>>>>
> >>>>>>>>> Vladimir Oltean (6):
> >>>>>>>>>            net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> >>>>>>>>>            net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> >>>>>>>>>            net: phy: ar803x: Use common functions for RGMII internal delays
> >>>>>>>>>            net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> >>>>>>>>>            net: phy: ar803x: Explicitly disable RGMII delays
> >>>>>>>>
> >>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> >>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
> >>>>>>>> AR8031/AR8033.
> >>>>>>>>
> >>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
> >>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> >>>>>>>> delay is now being disabled.
> >>>>>>>>
> >>>>>>>> Any thoughts, Vladimir?
> >>>>>>>>
> >>>>>>>> Thanks,
> >>>>>>>> -Joe
> >>>>>>>>
> >>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> >>>>>>>> [2] arch/arm/dts/am335x-evm.dts
> >>>>>>>>
> >>>>>>>>>            net: phy: ar803x: Clarify the intention of ar8021_config
> >>>>>>>>>
> >>>>>>>>>       arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> >>>>>>>>>       arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> >>>>>>>>>       arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> >>>>>>>>>       board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> >>>>>>>>>       cmd/mdio.c                                      |  27 +++--
> >>>>>>>>>       doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> >>>>>>>>>       drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> >>>>>>>>>       drivers/net/phy/Kconfig                         |  41 ++++++++
> >>>>>>>>>       drivers/net/phy/aquantia.c                      |   7 +-
> >>>>>>>>>       drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> >>>>>>>>>       drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> >>>>>>>>>       drivers/net/phy/phy.c                           |  21 +++-
> >>>>>>>>>       drivers/net/phy/realtek.c                       |  19 ++++
> >>>>>>>>>       drivers/net/phy/ti.c                            | 130 +++++-------------------
> >>>>>>>>>       include/phy.h                                   |  70 +++++++++++++
> >>>>>>>>>       19 files changed, 394 insertions(+), 221 deletions(-)
> >>>>>>>>>
> >>>>>>>>> Thanks!
> >>>>>>>>> -Joe
> >>>>>>>>> _______________________________________________
> >>>>>>>>> U-Boot mailing list
> >>>>>>>>> U-Boot@lists.denx.de
> >>>>>>>>> https://lists.denx.de/listinfo/u-boot
> >>>>>>>>
> >>>>>>>
> >>>>>>> Hi Joe, Tom,
> >>>>>>>
> >>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
> >>>>>>> causing link failure.
> >>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
> >>>>>>> correct RGMII timing budget, then for sure it was working before and now
> >>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
> >>>>>>> broken and should be corrected.
> >>>>>>> Sorry for the trouble this has caused.
> >>>>>>
> >>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
> >>>>>> there?
> >>>>>
> >>>>> On the latest net-next, it's handled the same: disable everything and
> >>>>> enable only what's specified in phy-mode. I didn't keep track of older
> >>>>> versions.
> >>>>
> >>>> So you would expect the network to be broken on net-next with this DTS?
> >>>> Because that's not allowed...
> >>>>
> >>>
> >>> Yes, if it's the same problem, the behavior should be the same.
> >>> I see net-next is only rejecting the bad DT since 2019-02-21:
> >>> https://patchwork.kernel.org/patch/10819279/
> >>> So it depends when you checked it last time.
> >>
> >> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
> >> there some work-around for the DTS so that ethernet works?
> >
> > Work-around in Linux or in U-boot?
> > U-boot can fix up the DT for Linux and replace "rgmii-txid" with
> > "rgmii-id", whereas neither Linux nor U-boot can do anything for
> > themselves except either load a correct DT blob, or not use (revert, not
> > upgrade to, etc) the enforcing patch.
> >
> >> You cannot break existing DTs
> > RGMII delay breakages happen all the time. To play the devil's advocate,
> > protecting against them should be done by observing the semantics
> > described in the devicetree/bindings document.
> > If you follow Linux net-next, a breakage for RTL8211F is planned out
> > right as we speak.
> >
> > But let's wait until we know for sure that this is what's causing the
> > issues.
> >
> > Regards,
> > -Vladimir
> >
>
> Hi Tom,
>
> I understand now what you mean by "workaround".
> Yes you can enable RGMII delays by hand in U-boot:
>
> Check if RX delay is enabled (bit 15 of debug register 0):
> => mdio write eTSEC1 0x1D 0
> => mdio read eTSEC1 0x1E
> => mdio write eTSEC1 0x1E <new value>
>
> Check if TX delay is enabled (bit 8 of debug register 5):
> => mdio write eTSEC1 0x1D 5
> => mdio read eTSEC1 0x1E
> => mdio write eTSEC1 0x1E <new value>
>
> Replace eTSEC1 with your net device from "mdio list".

I'm not sure what the follow-on action is here. I'll hold off on
Vladimir's series until there is a resolution that everyone is
satisfied with.

Cheers,
-Joe

Tom Rini May 15, 2019, 2:58 p.m. UTC | #13

On Fri, May 10, 2019 at 09:50:45PM +0000, Joe Hershberger wrote:
> Hi Vladimir and Tom,
> 
> On Thu, May 9, 2019 at 7:51 AM Vladimir Oltean <vladimir.oltean@nxp.com> wrote:
> >
> > On 09.05.2019 02:05, Vladimir Oltean wrote:
> > > On 5/9/19 1:55 AM, Tom Rini wrote:
> > >> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
> > >>> On 5/9/19 1:48 AM, Tom Rini wrote:
> > >>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> > >>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
> > >>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> > >>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> > >>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> > >>>>>>>>>
> > >>>>>>>>> Hi Tom,
> > >>>>>>>>>
> > >>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> > >>>>>>>>>
> > >>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> > >>>>>>>>> MLO also now fits again.
> > >>>>>>>>>
> > >>>>>>>>>        Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> > >>>>>>>>>
> > >>>>>>>>> are available in the git repository at:
> > >>>>>>>>>
> > >>>>>>>>>        git://git.denx.de/u-boot-net.git master
> > >>>>>>>>>
> > >>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> > >>>>>>>>>
> > >>>>>>>>>        net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> > >>>>>>>>>
> > >>>>>>>>> ----------------------------------------------------------------
> > >>>>>>>>> Carlo Caione (4):
> > >>>>>>>>>            net: phy: Add generic helpers to access MMD PHY registers
> > >>>>>>>>>            net: phy: ti: use generic helpers to access MMD registers
> > >>>>>>>>>            cmd: mdio: Switch to generic helpers when accessing the registers
> > >>>>>>>>>            net: phy: realtek: Introduce quirk to mark RXC not stoppable
> > >>>>>>>>>
> > >>>>>>>>> James Byrne (2):
> > >>>>>>>>>            net: phy: micrel: Use correct skew values on KSZ9021
> > >>>>>>>>>            net: phy: micrel: Find Micrel PHY node correctly
> > >>>>>>>>>
> > >>>>>>>>> Murali Karicheri (2):
> > >>>>>>>>>            ARM: k2g-gp-evm: update to rgmii pinmux configuration
> > >>>>>>>>>            ARM: k2g-ice: Add pinmux support for rgmii interface
> > >>>>>>>>>
> > >>>>>>>>> Pankaj Bansal (1):
> > >>>>>>>>>            drivers: net: ldpaa_eth: fix resource leak
> > >>>>>>>>>
> > >>>>>>>>> Siva Durga Prasad Paladugu (2):
> > >>>>>>>>>            net: phy: Reloc next and prev pointers inside phy_drivers
> > >>>>>>>>>            net: phy: Fix return value check phy_probe
> > >>>>>>>>>
> > >>>>>>>>> Valentin-catalin Neacsu (1):
> > >>>>>>>>>            net: phy: aquantia: Set only autoneg on in register 4.c441
> > >>>>>>>>>
> > >>>>>>>>> Vladimir Oltean (6):
> > >>>>>>>>>            net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> > >>>>>>>>>            net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> > >>>>>>>>>            net: phy: ar803x: Use common functions for RGMII internal delays
> > >>>>>>>>>            net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> > >>>>>>>>>            net: phy: ar803x: Explicitly disable RGMII delays
> > >>>>>>>>
> > >>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> > >>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
> > >>>>>>>> AR8031/AR8033.
> > >>>>>>>>
> > >>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
> > >>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> > >>>>>>>> delay is now being disabled.
> > >>>>>>>>
> > >>>>>>>> Any thoughts, Vladimir?
> > >>>>>>>>
> > >>>>>>>> Thanks,
> > >>>>>>>> -Joe
> > >>>>>>>>
> > >>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> > >>>>>>>> [2] arch/arm/dts/am335x-evm.dts
> > >>>>>>>>
> > >>>>>>>>>            net: phy: ar803x: Clarify the intention of ar8021_config
> > >>>>>>>>>
> > >>>>>>>>>       arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> > >>>>>>>>>       arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> > >>>>>>>>>       arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> > >>>>>>>>>       board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> > >>>>>>>>>       cmd/mdio.c                                      |  27 +++--
> > >>>>>>>>>       doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> > >>>>>>>>>       drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> > >>>>>>>>>       drivers/net/phy/Kconfig                         |  41 ++++++++
> > >>>>>>>>>       drivers/net/phy/aquantia.c                      |   7 +-
> > >>>>>>>>>       drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> > >>>>>>>>>       drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> > >>>>>>>>>       drivers/net/phy/phy.c                           |  21 +++-
> > >>>>>>>>>       drivers/net/phy/realtek.c                       |  19 ++++
> > >>>>>>>>>       drivers/net/phy/ti.c                            | 130 +++++-------------------
> > >>>>>>>>>       include/phy.h                                   |  70 +++++++++++++
> > >>>>>>>>>       19 files changed, 394 insertions(+), 221 deletions(-)
> > >>>>>>>>>
> > >>>>>>>>> Thanks!
> > >>>>>>>>> -Joe
> > >>>>>>>>> _______________________________________________
> > >>>>>>>>> U-Boot mailing list
> > >>>>>>>>> U-Boot@lists.denx.de
> > >>>>>>>>> https://lists.denx.de/listinfo/u-boot
> > >>>>>>>>
> > >>>>>>>
> > >>>>>>> Hi Joe, Tom,
> > >>>>>>>
> > >>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
> > >>>>>>> causing link failure.
> > >>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
> > >>>>>>> correct RGMII timing budget, then for sure it was working before and now
> > >>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
> > >>>>>>> broken and should be corrected.
> > >>>>>>> Sorry for the trouble this has caused.
> > >>>>>>
> > >>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
> > >>>>>> there?
> > >>>>>
> > >>>>> On the latest net-next, it's handled the same: disable everything and
> > >>>>> enable only what's specified in phy-mode. I didn't keep track of older
> > >>>>> versions.
> > >>>>
> > >>>> So you would expect the network to be broken on net-next with this DTS?
> > >>>> Because that's not allowed...
> > >>>>
> > >>>
> > >>> Yes, if it's the same problem, the behavior should be the same.
> > >>> I see net-next is only rejecting the bad DT since 2019-02-21:
> > >>> https://patchwork.kernel.org/patch/10819279/
> > >>> So it depends when you checked it last time.
> > >>
> > >> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
> > >> there some work-around for the DTS so that ethernet works?
> > >
> > > Work-around in Linux or in U-boot?
> > > U-boot can fix up the DT for Linux and replace "rgmii-txid" with
> > > "rgmii-id", whereas neither Linux nor U-boot can do anything for
> > > themselves except either load a correct DT blob, or not use (revert, not
> > > upgrade to, etc) the enforcing patch.
> > >
> > >> You cannot break existing DTs
> > > RGMII delay breakages happen all the time. To play the devil's advocate,
> > > protecting against them should be done by observing the semantics
> > > described in the devicetree/bindings document.
> > > If you follow Linux net-next, a breakage for RTL8211F is planned out
> > > right as we speak.
> > >
> > > But let's wait until we know for sure that this is what's causing the
> > > issues.
> > >
> > > Regards,
> > > -Vladimir
> > >
> >
> > Hi Tom,
> >
> > I understand now what you mean by "workaround".
> > Yes you can enable RGMII delays by hand in U-boot:
> >
> > Check if RX delay is enabled (bit 15 of debug register 0):
> > => mdio write eTSEC1 0x1D 0
> > => mdio read eTSEC1 0x1E
> > => mdio write eTSEC1 0x1E <new value>
> >
> > Check if TX delay is enabled (bit 8 of debug register 5):
> > => mdio write eTSEC1 0x1D 5
> > => mdio read eTSEC1 0x1E
> > => mdio write eTSEC1 0x1E <new value>
> >
> > Replace eTSEC1 with your net device from "mdio list".
> 
> I'm not sure what the follow-on action is here. I'll hold off on
> Vladimir's series until there is a resolution that everyone is
> satisfied with.

While I personally think this breaks the "DT is ABI" model, the required
change has already been merged into Linus' tree so we just need to
re-sync the am335x DTS files again and then we can apply these changes.
I'll put it on my TODO list.

Vladimir Oltean July 25, 2019, 10:40 p.m. UTC | #14

On 5/15/19 5:58 PM, Tom Rini wrote:
> On Fri, May 10, 2019 at 09:50:45PM +0000, Joe Hershberger wrote:
>> Hi Vladimir and Tom,
>>
>> On Thu, May 9, 2019 at 7:51 AM Vladimir Oltean <vladimir.oltean@nxp.com> wrote:
>>>
>>> On 09.05.2019 02:05, Vladimir Oltean wrote:
>>>> On 5/9/19 1:55 AM, Tom Rini wrote:
>>>>> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
>>>>>> On 5/9/19 1:48 AM, Tom Rini wrote:
>>>>>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
>>>>>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
>>>>>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
>>>>>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
>>>>>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>> Hi Tom,
>>>>>>>>>>>>
>>>>>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
>>>>>>>>>>>>
>>>>>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
>>>>>>>>>>>> MLO also now fits again.
>>>>>>>>>>>>
>>>>>>>>>>>>         Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
>>>>>>>>>>>>
>>>>>>>>>>>> are available in the git repository at:
>>>>>>>>>>>>
>>>>>>>>>>>>         git://git.denx.de/u-boot-net.git master
>>>>>>>>>>>>
>>>>>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
>>>>>>>>>>>>
>>>>>>>>>>>>         net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
>>>>>>>>>>>>
>>>>>>>>>>>> ----------------------------------------------------------------
>>>>>>>>>>>> Carlo Caione (4):
>>>>>>>>>>>>             net: phy: Add generic helpers to access MMD PHY registers
>>>>>>>>>>>>             net: phy: ti: use generic helpers to access MMD registers
>>>>>>>>>>>>             cmd: mdio: Switch to generic helpers when accessing the registers
>>>>>>>>>>>>             net: phy: realtek: Introduce quirk to mark RXC not stoppable
>>>>>>>>>>>>
>>>>>>>>>>>> James Byrne (2):
>>>>>>>>>>>>             net: phy: micrel: Use correct skew values on KSZ9021
>>>>>>>>>>>>             net: phy: micrel: Find Micrel PHY node correctly
>>>>>>>>>>>>
>>>>>>>>>>>> Murali Karicheri (2):
>>>>>>>>>>>>             ARM: k2g-gp-evm: update to rgmii pinmux configuration
>>>>>>>>>>>>             ARM: k2g-ice: Add pinmux support for rgmii interface
>>>>>>>>>>>>
>>>>>>>>>>>> Pankaj Bansal (1):
>>>>>>>>>>>>             drivers: net: ldpaa_eth: fix resource leak
>>>>>>>>>>>>
>>>>>>>>>>>> Siva Durga Prasad Paladugu (2):
>>>>>>>>>>>>             net: phy: Reloc next and prev pointers inside phy_drivers
>>>>>>>>>>>>             net: phy: Fix return value check phy_probe
>>>>>>>>>>>>
>>>>>>>>>>>> Valentin-catalin Neacsu (1):
>>>>>>>>>>>>             net: phy: aquantia: Set only autoneg on in register 4.c441
>>>>>>>>>>>>
>>>>>>>>>>>> Vladimir Oltean (6):
>>>>>>>>>>>>             net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
>>>>>>>>>>>>             net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
>>>>>>>>>>>>             net: phy: ar803x: Use common functions for RGMII internal delays
>>>>>>>>>>>>             net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
>>>>>>>>>>>>             net: phy: ar803x: Explicitly disable RGMII delays
>>>>>>>>>>>
>>>>>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
>>>>>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
>>>>>>>>>>> AR8031/AR8033.
>>>>>>>>>>>
>>>>>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
>>>>>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
>>>>>>>>>>> delay is now being disabled.
>>>>>>>>>>>
>>>>>>>>>>> Any thoughts, Vladimir?
>>>>>>>>>>>
>>>>>>>>>>> Thanks,
>>>>>>>>>>> -Joe
>>>>>>>>>>>
>>>>>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
>>>>>>>>>>> [2] arch/arm/dts/am335x-evm.dts
>>>>>>>>>>>
>>>>>>>>>>>>             net: phy: ar803x: Clarify the intention of ar8021_config
>>>>>>>>>>>>
>>>>>>>>>>>>        arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
>>>>>>>>>>>>        arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
>>>>>>>>>>>>        arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
>>>>>>>>>>>>        arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
>>>>>>>>>>>>        arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
>>>>>>>>>>>>        arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
>>>>>>>>>>>>        arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
>>>>>>>>>>>>        board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
>>>>>>>>>>>>        cmd/mdio.c                                      |  27 +++--
>>>>>>>>>>>>        doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
>>>>>>>>>>>>        drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
>>>>>>>>>>>>        drivers/net/phy/Kconfig                         |  41 ++++++++
>>>>>>>>>>>>        drivers/net/phy/aquantia.c                      |   7 +-
>>>>>>>>>>>>        drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
>>>>>>>>>>>>        drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
>>>>>>>>>>>>        drivers/net/phy/phy.c                           |  21 +++-
>>>>>>>>>>>>        drivers/net/phy/realtek.c                       |  19 ++++
>>>>>>>>>>>>        drivers/net/phy/ti.c                            | 130 +++++-------------------
>>>>>>>>>>>>        include/phy.h                                   |  70 +++++++++++++
>>>>>>>>>>>>        19 files changed, 394 insertions(+), 221 deletions(-)
>>>>>>>>>>>>
>>>>>>>>>>>> Thanks!
>>>>>>>>>>>> -Joe
>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>> U-Boot mailing list
>>>>>>>>>>>> U-Boot@lists.denx.de
>>>>>>>>>>>> https://lists.denx.de/listinfo/u-boot
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Hi Joe, Tom,
>>>>>>>>>>
>>>>>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
>>>>>>>>>> causing link failure.
>>>>>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
>>>>>>>>>> correct RGMII timing budget, then for sure it was working before and now
>>>>>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
>>>>>>>>>> broken and should be corrected.
>>>>>>>>>> Sorry for the trouble this has caused.
>>>>>>>>>
>>>>>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
>>>>>>>>> there?
>>>>>>>>
>>>>>>>> On the latest net-next, it's handled the same: disable everything and
>>>>>>>> enable only what's specified in phy-mode. I didn't keep track of older
>>>>>>>> versions.
>>>>>>>
>>>>>>> So you would expect the network to be broken on net-next with this DTS?
>>>>>>> Because that's not allowed...
>>>>>>>
>>>>>>
>>>>>> Yes, if it's the same problem, the behavior should be the same.
>>>>>> I see net-next is only rejecting the bad DT since 2019-02-21:
>>>>>> https://patchwork.kernel.org/patch/10819279/
>>>>>> So it depends when you checked it last time.
>>>>>
>>>>> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
>>>>> there some work-around for the DTS so that ethernet works?
>>>>
>>>> Work-around in Linux or in U-boot?
>>>> U-boot can fix up the DT for Linux and replace "rgmii-txid" with
>>>> "rgmii-id", whereas neither Linux nor U-boot can do anything for
>>>> themselves except either load a correct DT blob, or not use (revert, not
>>>> upgrade to, etc) the enforcing patch.
>>>>
>>>>> You cannot break existing DTs
>>>> RGMII delay breakages happen all the time. To play the devil's advocate,
>>>> protecting against them should be done by observing the semantics
>>>> described in the devicetree/bindings document.
>>>> If you follow Linux net-next, a breakage for RTL8211F is planned out
>>>> right as we speak.
>>>>
>>>> But let's wait until we know for sure that this is what's causing the
>>>> issues.
>>>>
>>>> Regards,
>>>> -Vladimir
>>>>
>>>
>>> Hi Tom,
>>>
>>> I understand now what you mean by "workaround".
>>> Yes you can enable RGMII delays by hand in U-boot:
>>>
>>> Check if RX delay is enabled (bit 15 of debug register 0):
>>> => mdio write eTSEC1 0x1D 0
>>> => mdio read eTSEC1 0x1E
>>> => mdio write eTSEC1 0x1E <new value>
>>>
>>> Check if TX delay is enabled (bit 8 of debug register 5):
>>> => mdio write eTSEC1 0x1D 5
>>> => mdio read eTSEC1 0x1E
>>> => mdio write eTSEC1 0x1E <new value>
>>>
>>> Replace eTSEC1 with your net device from "mdio list".
>>
>> I'm not sure what the follow-on action is here. I'll hold off on
>> Vladimir's series until there is a resolution that everyone is
>> satisfied with.
> 
> While I personally think this breaks the "DT is ABI" model, the required
> change has already been merged into Linus' tree so we just need to
> re-sync the am335x DTS files again and then we can apply these changes.
> I'll put it on my TODO list.
> 

Hi Tom, Joe,

It's been a long while - what is the latest news on RGMII delays for the 
am335x + Atheros PHY? I'd like to know whether Joe can pick up these 
patches again. As you more-or-less admitted, it's not really ABI 
breakage if the DT semantics were never properly followed in the first 
place.

Thanks,
-Vladimir

Tom Rini July 25, 2019, 11:12 p.m. UTC | #15

On Thu, Jul 25, 2019 at 10:40:45PM +0000, Vladimir Oltean wrote:
> On 5/15/19 5:58 PM, Tom Rini wrote:
> > On Fri, May 10, 2019 at 09:50:45PM +0000, Joe Hershberger wrote:
> >> Hi Vladimir and Tom,
> >>
> >> On Thu, May 9, 2019 at 7:51 AM Vladimir Oltean <vladimir.oltean@nxp.com> wrote:
> >>>
> >>> On 09.05.2019 02:05, Vladimir Oltean wrote:
> >>>> On 5/9/19 1:55 AM, Tom Rini wrote:
> >>>>> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
> >>>>>> On 5/9/19 1:48 AM, Tom Rini wrote:
> >>>>>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> >>>>>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
> >>>>>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> >>>>>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> >>>>>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> >>>>>>>>>>>>
> >>>>>>>>>>>> Hi Tom,
> >>>>>>>>>>>>
> >>>>>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> >>>>>>>>>>>>
> >>>>>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> >>>>>>>>>>>> MLO also now fits again.
> >>>>>>>>>>>>
> >>>>>>>>>>>>         Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> >>>>>>>>>>>>
> >>>>>>>>>>>> are available in the git repository at:
> >>>>>>>>>>>>
> >>>>>>>>>>>>         git://git.denx.de/u-boot-net.git master
> >>>>>>>>>>>>
> >>>>>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> >>>>>>>>>>>>
> >>>>>>>>>>>>         net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> >>>>>>>>>>>>
> >>>>>>>>>>>> ----------------------------------------------------------------
> >>>>>>>>>>>> Carlo Caione (4):
> >>>>>>>>>>>>             net: phy: Add generic helpers to access MMD PHY registers
> >>>>>>>>>>>>             net: phy: ti: use generic helpers to access MMD registers
> >>>>>>>>>>>>             cmd: mdio: Switch to generic helpers when accessing the registers
> >>>>>>>>>>>>             net: phy: realtek: Introduce quirk to mark RXC not stoppable
> >>>>>>>>>>>>
> >>>>>>>>>>>> James Byrne (2):
> >>>>>>>>>>>>             net: phy: micrel: Use correct skew values on KSZ9021
> >>>>>>>>>>>>             net: phy: micrel: Find Micrel PHY node correctly
> >>>>>>>>>>>>
> >>>>>>>>>>>> Murali Karicheri (2):
> >>>>>>>>>>>>             ARM: k2g-gp-evm: update to rgmii pinmux configuration
> >>>>>>>>>>>>             ARM: k2g-ice: Add pinmux support for rgmii interface
> >>>>>>>>>>>>
> >>>>>>>>>>>> Pankaj Bansal (1):
> >>>>>>>>>>>>             drivers: net: ldpaa_eth: fix resource leak
> >>>>>>>>>>>>
> >>>>>>>>>>>> Siva Durga Prasad Paladugu (2):
> >>>>>>>>>>>>             net: phy: Reloc next and prev pointers inside phy_drivers
> >>>>>>>>>>>>             net: phy: Fix return value check phy_probe
> >>>>>>>>>>>>
> >>>>>>>>>>>> Valentin-catalin Neacsu (1):
> >>>>>>>>>>>>             net: phy: aquantia: Set only autoneg on in register 4.c441
> >>>>>>>>>>>>
> >>>>>>>>>>>> Vladimir Oltean (6):
> >>>>>>>>>>>>             net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> >>>>>>>>>>>>             net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> >>>>>>>>>>>>             net: phy: ar803x: Use common functions for RGMII internal delays
> >>>>>>>>>>>>             net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> >>>>>>>>>>>>             net: phy: ar803x: Explicitly disable RGMII delays
> >>>>>>>>>>>
> >>>>>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> >>>>>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
> >>>>>>>>>>> AR8031/AR8033.
> >>>>>>>>>>>
> >>>>>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
> >>>>>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> >>>>>>>>>>> delay is now being disabled.
> >>>>>>>>>>>
> >>>>>>>>>>> Any thoughts, Vladimir?
> >>>>>>>>>>>
> >>>>>>>>>>> Thanks,
> >>>>>>>>>>> -Joe
> >>>>>>>>>>>
> >>>>>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> >>>>>>>>>>> [2] arch/arm/dts/am335x-evm.dts
> >>>>>>>>>>>
> >>>>>>>>>>>>             net: phy: ar803x: Clarify the intention of ar8021_config
> >>>>>>>>>>>>
> >>>>>>>>>>>>        arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> >>>>>>>>>>>>        arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> >>>>>>>>>>>>        arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> >>>>>>>>>>>>        arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> >>>>>>>>>>>>        arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> >>>>>>>>>>>>        arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> >>>>>>>>>>>>        arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> >>>>>>>>>>>>        board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> >>>>>>>>>>>>        cmd/mdio.c                                      |  27 +++--
> >>>>>>>>>>>>        doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> >>>>>>>>>>>>        drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> >>>>>>>>>>>>        drivers/net/phy/Kconfig                         |  41 ++++++++
> >>>>>>>>>>>>        drivers/net/phy/aquantia.c                      |   7 +-
> >>>>>>>>>>>>        drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> >>>>>>>>>>>>        drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> >>>>>>>>>>>>        drivers/net/phy/phy.c                           |  21 +++-
> >>>>>>>>>>>>        drivers/net/phy/realtek.c                       |  19 ++++
> >>>>>>>>>>>>        drivers/net/phy/ti.c                            | 130 +++++-------------------
> >>>>>>>>>>>>        include/phy.h                                   |  70 +++++++++++++
> >>>>>>>>>>>>        19 files changed, 394 insertions(+), 221 deletions(-)
> >>>>>>>>>>>>
> >>>>>>>>>>>> Thanks!
> >>>>>>>>>>>> -Joe
> >>>>>>>>>>>> _______________________________________________
> >>>>>>>>>>>> U-Boot mailing list
> >>>>>>>>>>>> U-Boot@lists.denx.de
> >>>>>>>>>>>> https://lists.denx.de/listinfo/u-boot
> >>>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> Hi Joe, Tom,
> >>>>>>>>>>
> >>>>>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
> >>>>>>>>>> causing link failure.
> >>>>>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
> >>>>>>>>>> correct RGMII timing budget, then for sure it was working before and now
> >>>>>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
> >>>>>>>>>> broken and should be corrected.
> >>>>>>>>>> Sorry for the trouble this has caused.
> >>>>>>>>>
> >>>>>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
> >>>>>>>>> there?
> >>>>>>>>
> >>>>>>>> On the latest net-next, it's handled the same: disable everything and
> >>>>>>>> enable only what's specified in phy-mode. I didn't keep track of older
> >>>>>>>> versions.
> >>>>>>>
> >>>>>>> So you would expect the network to be broken on net-next with this DTS?
> >>>>>>> Because that's not allowed...
> >>>>>>>
> >>>>>>
> >>>>>> Yes, if it's the same problem, the behavior should be the same.
> >>>>>> I see net-next is only rejecting the bad DT since 2019-02-21:
> >>>>>> https://patchwork.kernel.org/patch/10819279/
> >>>>>> So it depends when you checked it last time.
> >>>>>
> >>>>> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
> >>>>> there some work-around for the DTS so that ethernet works?
> >>>>
> >>>> Work-around in Linux or in U-boot?
> >>>> U-boot can fix up the DT for Linux and replace "rgmii-txid" with
> >>>> "rgmii-id", whereas neither Linux nor U-boot can do anything for
> >>>> themselves except either load a correct DT blob, or not use (revert, not
> >>>> upgrade to, etc) the enforcing patch.
> >>>>
> >>>>> You cannot break existing DTs
> >>>> RGMII delay breakages happen all the time. To play the devil's advocate,
> >>>> protecting against them should be done by observing the semantics
> >>>> described in the devicetree/bindings document.
> >>>> If you follow Linux net-next, a breakage for RTL8211F is planned out
> >>>> right as we speak.
> >>>>
> >>>> But let's wait until we know for sure that this is what's causing the
> >>>> issues.
> >>>>
> >>>> Regards,
> >>>> -Vladimir
> >>>>
> >>>
> >>> Hi Tom,
> >>>
> >>> I understand now what you mean by "workaround".
> >>> Yes you can enable RGMII delays by hand in U-boot:
> >>>
> >>> Check if RX delay is enabled (bit 15 of debug register 0):
> >>> => mdio write eTSEC1 0x1D 0
> >>> => mdio read eTSEC1 0x1E
> >>> => mdio write eTSEC1 0x1E <new value>
> >>>
> >>> Check if TX delay is enabled (bit 8 of debug register 5):
> >>> => mdio write eTSEC1 0x1D 5
> >>> => mdio read eTSEC1 0x1E
> >>> => mdio write eTSEC1 0x1E <new value>
> >>>
> >>> Replace eTSEC1 with your net device from "mdio list".
> >>
> >> I'm not sure what the follow-on action is here. I'll hold off on
> >> Vladimir's series until there is a resolution that everyone is
> >> satisfied with.
> > 
> > While I personally think this breaks the "DT is ABI" model, the required
> > change has already been merged into Linus' tree so we just need to
> > re-sync the am335x DTS files again and then we can apply these changes.
> > I'll put it on my TODO list.
> > 
> 
> Hi Tom, Joe,
> 
> It's been a long while - what is the latest news on RGMII delays for the 
> am335x + Atheros PHY? I'd like to know whether Joe can pick up these 
> patches again. As you more-or-less admitted, it's not really ABI 
> breakage if the DT semantics were never properly followed in the first 
> place.

It's ABI breakage that no one cared about.  At this point, it's blocked
until the am335x DTS files get a resync from the kernel and that's
somewhere on my TODO list.

Michael Walle Nov. 2, 2019, 1:17 p.m. UTC | #16

Am 2019-05-15 16:58, schrieb Tom Rini:
> On Fri, May 10, 2019 at 09:50:45PM +0000, Joe Hershberger wrote:
>> Hi Vladimir and Tom,
>> 
>> On Thu, May 9, 2019 at 7:51 AM Vladimir Oltean 
>> <vladimir.oltean@nxp.com> wrote:
>> >
>> > On 09.05.2019 02:05, Vladimir Oltean wrote:
>> > > On 5/9/19 1:55 AM, Tom Rini wrote:
>> > >> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
>> > >>> On 5/9/19 1:48 AM, Tom Rini wrote:
>> > >>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
>> > >>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
>> > >>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
>> > >>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
>> > >>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
>> > >>>>>>>>>
>> > >>>>>>>>> Hi Tom,
>> > >>>>>>>>>
>> > >>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
>> > >>>>>>>>>
>> > >>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
>> > >>>>>>>>> MLO also now fits again.
>> > >>>>>>>>>
>> > >>>>>>>>>        Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
>> > >>>>>>>>>
>> > >>>>>>>>> are available in the git repository at:
>> > >>>>>>>>>
>> > >>>>>>>>>        git://git.denx.de/u-boot-net.git master
>> > >>>>>>>>>
>> > >>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
>> > >>>>>>>>>
>> > >>>>>>>>>        net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
>> > >>>>>>>>>
>> > >>>>>>>>> ----------------------------------------------------------------
>> > >>>>>>>>> Carlo Caione (4):
>> > >>>>>>>>>            net: phy: Add generic helpers to access MMD PHY registers
>> > >>>>>>>>>            net: phy: ti: use generic helpers to access MMD registers
>> > >>>>>>>>>            cmd: mdio: Switch to generic helpers when accessing the registers
>> > >>>>>>>>>            net: phy: realtek: Introduce quirk to mark RXC not stoppable
>> > >>>>>>>>>
>> > >>>>>>>>> James Byrne (2):
>> > >>>>>>>>>            net: phy: micrel: Use correct skew values on KSZ9021
>> > >>>>>>>>>            net: phy: micrel: Find Micrel PHY node correctly
>> > >>>>>>>>>
>> > >>>>>>>>> Murali Karicheri (2):
>> > >>>>>>>>>            ARM: k2g-gp-evm: update to rgmii pinmux configuration
>> > >>>>>>>>>            ARM: k2g-ice: Add pinmux support for rgmii interface
>> > >>>>>>>>>
>> > >>>>>>>>> Pankaj Bansal (1):
>> > >>>>>>>>>            drivers: net: ldpaa_eth: fix resource leak
>> > >>>>>>>>>
>> > >>>>>>>>> Siva Durga Prasad Paladugu (2):
>> > >>>>>>>>>            net: phy: Reloc next and prev pointers inside phy_drivers
>> > >>>>>>>>>            net: phy: Fix return value check phy_probe
>> > >>>>>>>>>
>> > >>>>>>>>> Valentin-catalin Neacsu (1):
>> > >>>>>>>>>            net: phy: aquantia: Set only autoneg on in register 4.c441
>> > >>>>>>>>>
>> > >>>>>>>>> Vladimir Oltean (6):
>> > >>>>>>>>>            net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
>> > >>>>>>>>>            net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
>> > >>>>>>>>>            net: phy: ar803x: Use common functions for RGMII internal delays
>> > >>>>>>>>>            net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
>> > >>>>>>>>>            net: phy: ar803x: Explicitly disable RGMII delays
>> > >>>>>>>>
>> > >>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
>> > >>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
>> > >>>>>>>> AR8031/AR8033.
>> > >>>>>>>>
>> > >>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
>> > >>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
>> > >>>>>>>> delay is now being disabled.
>> > >>>>>>>>
>> > >>>>>>>> Any thoughts, Vladimir?
>> > >>>>>>>>
>> > >>>>>>>> Thanks,
>> > >>>>>>>> -Joe
>> > >>>>>>>>
>> > >>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
>> > >>>>>>>> [2] arch/arm/dts/am335x-evm.dts
>> > >>>>>>>>
>> > >>>>>>>>>            net: phy: ar803x: Clarify the intention of ar8021_config
>> > >>>>>>>>>
>> > >>>>>>>>>       arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
>> > >>>>>>>>>       arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
>> > >>>>>>>>>       arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
>> > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
>> > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
>> > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
>> > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
>> > >>>>>>>>>       board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
>> > >>>>>>>>>       cmd/mdio.c                                      |  27 +++--
>> > >>>>>>>>>       doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
>> > >>>>>>>>>       drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
>> > >>>>>>>>>       drivers/net/phy/Kconfig                         |  41 ++++++++
>> > >>>>>>>>>       drivers/net/phy/aquantia.c                      |   7 +-
>> > >>>>>>>>>       drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
>> > >>>>>>>>>       drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
>> > >>>>>>>>>       drivers/net/phy/phy.c                           |  21 +++-
>> > >>>>>>>>>       drivers/net/phy/realtek.c                       |  19 ++++
>> > >>>>>>>>>       drivers/net/phy/ti.c                            | 130 +++++-------------------
>> > >>>>>>>>>       include/phy.h                                   |  70 +++++++++++++
>> > >>>>>>>>>       19 files changed, 394 insertions(+), 221 deletions(-)
>> > >>>>>>>>>
>> > >>>>>>>>> Thanks!
>> > >>>>>>>>> -Joe
>> > >>>>>>>>> _______________________________________________
>> > >>>>>>>>> U-Boot mailing list
>> > >>>>>>>>> U-Boot@lists.denx.de
>> > >>>>>>>>> https://lists.denx.de/listinfo/u-boot
>> > >>>>>>>>
>> > >>>>>>>
>> > >>>>>>> Hi Joe, Tom,
>> > >>>>>>>
>> > >>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
>> > >>>>>>> causing link failure.
>> > >>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
>> > >>>>>>> correct RGMII timing budget, then for sure it was working before and now
>> > >>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
>> > >>>>>>> broken and should be corrected.
>> > >>>>>>> Sorry for the trouble this has caused.
>> > >>>>>>
>> > >>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
>> > >>>>>> there?
>> > >>>>>
>> > >>>>> On the latest net-next, it's handled the same: disable everything and
>> > >>>>> enable only what's specified in phy-mode. I didn't keep track of older
>> > >>>>> versions.
>> > >>>>
>> > >>>> So you would expect the network to be broken on net-next with this DTS?
>> > >>>> Because that's not allowed...
>> > >>>>
>> > >>>
>> > >>> Yes, if it's the same problem, the behavior should be the same.
>> > >>> I see net-next is only rejecting the bad DT since 2019-02-21:
>> > >>> https://patchwork.kernel.org/patch/10819279/
>> > >>> So it depends when you checked it last time.
>> > >>
>> > >> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
>> > >> there some work-around for the DTS so that ethernet works?
>> > >
>> > > Work-around in Linux or in U-boot?
>> > > U-boot can fix up the DT for Linux and replace "rgmii-txid" with
>> > > "rgmii-id", whereas neither Linux nor U-boot can do anything for
>> > > themselves except either load a correct DT blob, or not use (revert, not
>> > > upgrade to, etc) the enforcing patch.
>> > >
>> > >> You cannot break existing DTs
>> > > RGMII delay breakages happen all the time. To play the devil's advocate,
>> > > protecting against them should be done by observing the semantics
>> > > described in the devicetree/bindings document.
>> > > If you follow Linux net-next, a breakage for RTL8211F is planned out
>> > > right as we speak.
>> > >
>> > > But let's wait until we know for sure that this is what's causing the
>> > > issues.
>> > >
>> > > Regards,
>> > > -Vladimir
>> > >
>> >
>> > Hi Tom,
>> >
>> > I understand now what you mean by "workaround".
>> > Yes you can enable RGMII delays by hand in U-boot:
>> >
>> > Check if RX delay is enabled (bit 15 of debug register 0):
>> > => mdio write eTSEC1 0x1D 0
>> > => mdio read eTSEC1 0x1E
>> > => mdio write eTSEC1 0x1E <new value>
>> >
>> > Check if TX delay is enabled (bit 8 of debug register 5):
>> > => mdio write eTSEC1 0x1D 5
>> > => mdio read eTSEC1 0x1E
>> > => mdio write eTSEC1 0x1E <new value>
>> >
>> > Replace eTSEC1 with your net device from "mdio list".
>> 
>> I'm not sure what the follow-on action is here. I'll hold off on
>> Vladimir's series until there is a resolution that everyone is
>> satisfied with.
> 
> While I personally think this breaks the "DT is ABI" model, the 
> required
> change has already been merged into Linus' tree so we just need to
> re-sync the am335x DTS files again and then we can apply these changes.
> I'll put it on my TODO list.

Hi,

sorry for pulling up such an old thread. Are there any news on this? 
Because I've had the same fix for the atheros PHYs posted to the u-boot 
mailing list lately (without knowing anything about this thread).

So with that rule "don't break old (and very wrong!) DT blobs" we seem 
not to be able to fix any serious errors. Because while it works for the 
most cases eg. phy-mode = rgmii-id, it wont work (and cant be fixed!) 
for rgmii-txid (or was it rxid? the one where the hardware default is 
enabled).

I could also post my series without fixing that issue and just adding 
clock support. But I'd rather see that fixed.

Thats just my two cents.

-michael

Tom Rini Nov. 2, 2019, 2:12 p.m. UTC | #17

On Sat, Nov 02, 2019 at 02:17:28PM +0100, Michael Walle wrote:
> Am 2019-05-15 16:58, schrieb Tom Rini:
> > On Fri, May 10, 2019 at 09:50:45PM +0000, Joe Hershberger wrote:
> > > Hi Vladimir and Tom,
> > > 
> > > On Thu, May 9, 2019 at 7:51 AM Vladimir Oltean
> > > <vladimir.oltean@nxp.com> wrote:
> > > >
> > > > On 09.05.2019 02:05, Vladimir Oltean wrote:
> > > > > On 5/9/19 1:55 AM, Tom Rini wrote:
> > > > >> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
> > > > >>> On 5/9/19 1:48 AM, Tom Rini wrote:
> > > > >>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> > > > >>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
> > > > >>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> > > > >>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> > > > >>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> > > > >>>>>>>>>
> > > > >>>>>>>>> Hi Tom,
> > > > >>>>>>>>>
> > > > >>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> > > > >>>>>>>>>
> > > > >>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> > > > >>>>>>>>> MLO also now fits again.
> > > > >>>>>>>>>
> > > > >>>>>>>>>        Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> > > > >>>>>>>>>
> > > > >>>>>>>>> are available in the git repository at:
> > > > >>>>>>>>>
> > > > >>>>>>>>>        git://git.denx.de/u-boot-net.git master
> > > > >>>>>>>>>
> > > > >>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> > > > >>>>>>>>>
> > > > >>>>>>>>>        net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> > > > >>>>>>>>>
> > > > >>>>>>>>> ----------------------------------------------------------------
> > > > >>>>>>>>> Carlo Caione (4):
> > > > >>>>>>>>>            net: phy: Add generic helpers to access MMD PHY registers
> > > > >>>>>>>>>            net: phy: ti: use generic helpers to access MMD registers
> > > > >>>>>>>>>            cmd: mdio: Switch to generic helpers when accessing the registers
> > > > >>>>>>>>>            net: phy: realtek: Introduce quirk to mark RXC not stoppable
> > > > >>>>>>>>>
> > > > >>>>>>>>> James Byrne (2):
> > > > >>>>>>>>>            net: phy: micrel: Use correct skew values on KSZ9021
> > > > >>>>>>>>>            net: phy: micrel: Find Micrel PHY node correctly
> > > > >>>>>>>>>
> > > > >>>>>>>>> Murali Karicheri (2):
> > > > >>>>>>>>>            ARM: k2g-gp-evm: update to rgmii pinmux configuration
> > > > >>>>>>>>>            ARM: k2g-ice: Add pinmux support for rgmii interface
> > > > >>>>>>>>>
> > > > >>>>>>>>> Pankaj Bansal (1):
> > > > >>>>>>>>>            drivers: net: ldpaa_eth: fix resource leak
> > > > >>>>>>>>>
> > > > >>>>>>>>> Siva Durga Prasad Paladugu (2):
> > > > >>>>>>>>>            net: phy: Reloc next and prev pointers inside phy_drivers
> > > > >>>>>>>>>            net: phy: Fix return value check phy_probe
> > > > >>>>>>>>>
> > > > >>>>>>>>> Valentin-catalin Neacsu (1):
> > > > >>>>>>>>>            net: phy: aquantia: Set only autoneg on in register 4.c441
> > > > >>>>>>>>>
> > > > >>>>>>>>> Vladimir Oltean (6):
> > > > >>>>>>>>>            net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> > > > >>>>>>>>>            net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> > > > >>>>>>>>>            net: phy: ar803x: Use common functions for RGMII internal delays
> > > > >>>>>>>>>            net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> > > > >>>>>>>>>            net: phy: ar803x: Explicitly disable RGMII delays
> > > > >>>>>>>>
> > > > >>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> > > > >>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
> > > > >>>>>>>> AR8031/AR8033.
> > > > >>>>>>>>
> > > > >>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
> > > > >>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> > > > >>>>>>>> delay is now being disabled.
> > > > >>>>>>>>
> > > > >>>>>>>> Any thoughts, Vladimir?
> > > > >>>>>>>>
> > > > >>>>>>>> Thanks,
> > > > >>>>>>>> -Joe
> > > > >>>>>>>>
> > > > >>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> > > > >>>>>>>> [2] arch/arm/dts/am335x-evm.dts
> > > > >>>>>>>>
> > > > >>>>>>>>>            net: phy: ar803x: Clarify the intention of ar8021_config
> > > > >>>>>>>>>
> > > > >>>>>>>>>       arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> > > > >>>>>>>>>       arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> > > > >>>>>>>>>       arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> > > > >>>>>>>>>       board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> > > > >>>>>>>>>       cmd/mdio.c                                      |  27 +++--
> > > > >>>>>>>>>       doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> > > > >>>>>>>>>       drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> > > > >>>>>>>>>       drivers/net/phy/Kconfig                         |  41 ++++++++
> > > > >>>>>>>>>       drivers/net/phy/aquantia.c                      |   7 +-
> > > > >>>>>>>>>       drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> > > > >>>>>>>>>       drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> > > > >>>>>>>>>       drivers/net/phy/phy.c                           |  21 +++-
> > > > >>>>>>>>>       drivers/net/phy/realtek.c                       |  19 ++++
> > > > >>>>>>>>>       drivers/net/phy/ti.c                            | 130 +++++-------------------
> > > > >>>>>>>>>       include/phy.h                                   |  70 +++++++++++++
> > > > >>>>>>>>>       19 files changed, 394 insertions(+), 221 deletions(-)
> > > > >>>>>>>>>
> > > > >>>>>>>>> Thanks!
> > > > >>>>>>>>> -Joe
> > > > >>>>>>>>> _______________________________________________
> > > > >>>>>>>>> U-Boot mailing list
> > > > >>>>>>>>> U-Boot@lists.denx.de
> > > > >>>>>>>>> https://lists.denx.de/listinfo/u-boot
> > > > >>>>>>>>
> > > > >>>>>>>
> > > > >>>>>>> Hi Joe, Tom,
> > > > >>>>>>>
> > > > >>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
> > > > >>>>>>> causing link failure.
> > > > >>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
> > > > >>>>>>> correct RGMII timing budget, then for sure it was working before and now
> > > > >>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
> > > > >>>>>>> broken and should be corrected.
> > > > >>>>>>> Sorry for the trouble this has caused.
> > > > >>>>>>
> > > > >>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
> > > > >>>>>> there?
> > > > >>>>>
> > > > >>>>> On the latest net-next, it's handled the same: disable everything and
> > > > >>>>> enable only what's specified in phy-mode. I didn't keep track of older
> > > > >>>>> versions.
> > > > >>>>
> > > > >>>> So you would expect the network to be broken on net-next with this DTS?
> > > > >>>> Because that's not allowed...
> > > > >>>>
> > > > >>>
> > > > >>> Yes, if it's the same problem, the behavior should be the same.
> > > > >>> I see net-next is only rejecting the bad DT since 2019-02-21:
> > > > >>> https://patchwork.kernel.org/patch/10819279/
> > > > >>> So it depends when you checked it last time.
> > > > >>
> > > > >> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
> > > > >> there some work-around for the DTS so that ethernet works?
> > > > >
> > > > > Work-around in Linux or in U-boot?
> > > > > U-boot can fix up the DT for Linux and replace "rgmii-txid" with
> > > > > "rgmii-id", whereas neither Linux nor U-boot can do anything for
> > > > > themselves except either load a correct DT blob, or not use (revert, not
> > > > > upgrade to, etc) the enforcing patch.
> > > > >
> > > > >> You cannot break existing DTs
> > > > > RGMII delay breakages happen all the time. To play the devil's advocate,
> > > > > protecting against them should be done by observing the semantics
> > > > > described in the devicetree/bindings document.
> > > > > If you follow Linux net-next, a breakage for RTL8211F is planned out
> > > > > right as we speak.
> > > > >
> > > > > But let's wait until we know for sure that this is what's causing the
> > > > > issues.
> > > > >
> > > > > Regards,
> > > > > -Vladimir
> > > > >
> > > >
> > > > Hi Tom,
> > > >
> > > > I understand now what you mean by "workaround".
> > > > Yes you can enable RGMII delays by hand in U-boot:
> > > >
> > > > Check if RX delay is enabled (bit 15 of debug register 0):
> > > > => mdio write eTSEC1 0x1D 0
> > > > => mdio read eTSEC1 0x1E
> > > > => mdio write eTSEC1 0x1E <new value>
> > > >
> > > > Check if TX delay is enabled (bit 8 of debug register 5):
> > > > => mdio write eTSEC1 0x1D 5
> > > > => mdio read eTSEC1 0x1E
> > > > => mdio write eTSEC1 0x1E <new value>
> > > >
> > > > Replace eTSEC1 with your net device from "mdio list".
> > > 
> > > I'm not sure what the follow-on action is here. I'll hold off on
> > > Vladimir's series until there is a resolution that everyone is
> > > satisfied with.
> > 
> > While I personally think this breaks the "DT is ABI" model, the required
> > change has already been merged into Linus' tree so we just need to
> > re-sync the am335x DTS files again and then we can apply these changes.
> > I'll put it on my TODO list.
> 
> Hi,
> 
> sorry for pulling up such an old thread. Are there any news on this? Because
> I've had the same fix for the atheros PHYs posted to the u-boot mailing list
> lately (without knowing anything about this thread).
> 
> So with that rule "don't break old (and very wrong!) DT blobs" we seem not
> to be able to fix any serious errors. Because while it works for the most
> cases eg. phy-mode = rgmii-id, it wont work (and cant be fixed!) for
> rgmii-txid (or was it rxid? the one where the hardware default is enabled).
> 
> I could also post my series without fixing that issue and just adding clock
> support. But I'd rather see that fixed.

So, there's patches to fix / keep cpsw working in U-Boot.  So while I
believe that Linux broke the rule of "DT is ABI" I've also gone
(virtually) hoarse pointing this out to the people that were supposed to
care.  So it's on my short list to grab the changes that are needed for
the TI platforms and we can grab all of the other changes as well.

Vladimir Oltean Nov. 2, 2019, 2:30 p.m. UTC | #18

On Sat, 2 Nov 2019 at 16:12, Tom Rini <trini@konsulko.com> wrote:
>
> On Sat, Nov 02, 2019 at 02:17:28PM +0100, Michael Walle wrote:
> > Am 2019-05-15 16:58, schrieb Tom Rini:
> > > On Fri, May 10, 2019 at 09:50:45PM +0000, Joe Hershberger wrote:
> > > > Hi Vladimir and Tom,
> > > >
> > > > On Thu, May 9, 2019 at 7:51 AM Vladimir Oltean
> > > > <vladimir.oltean@nxp.com> wrote:
> > > > >
> > > > > On 09.05.2019 02:05, Vladimir Oltean wrote:
> > > > > > On 5/9/19 1:55 AM, Tom Rini wrote:
> > > > > >> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
> > > > > >>> On 5/9/19 1:48 AM, Tom Rini wrote:
> > > > > >>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> > > > > >>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
> > > > > >>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> > > > > >>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> > > > > >>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> Hi Tom,
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> > > > > >>>>>>>>> MLO also now fits again.
> > > > > >>>>>>>>>
> > > > > >>>>>>>>>        Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> are available in the git repository at:
> > > > > >>>>>>>>>
> > > > > >>>>>>>>>        git://git.denx.de/u-boot-net.git master
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> > > > > >>>>>>>>>
> > > > > >>>>>>>>>        net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> ----------------------------------------------------------------
> > > > > >>>>>>>>> Carlo Caione (4):
> > > > > >>>>>>>>>            net: phy: Add generic helpers to access MMD PHY registers
> > > > > >>>>>>>>>            net: phy: ti: use generic helpers to access MMD registers
> > > > > >>>>>>>>>            cmd: mdio: Switch to generic helpers when accessing the registers
> > > > > >>>>>>>>>            net: phy: realtek: Introduce quirk to mark RXC not stoppable
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> James Byrne (2):
> > > > > >>>>>>>>>            net: phy: micrel: Use correct skew values on KSZ9021
> > > > > >>>>>>>>>            net: phy: micrel: Find Micrel PHY node correctly
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> Murali Karicheri (2):
> > > > > >>>>>>>>>            ARM: k2g-gp-evm: update to rgmii pinmux configuration
> > > > > >>>>>>>>>            ARM: k2g-ice: Add pinmux support for rgmii interface
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> Pankaj Bansal (1):
> > > > > >>>>>>>>>            drivers: net: ldpaa_eth: fix resource leak
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> Siva Durga Prasad Paladugu (2):
> > > > > >>>>>>>>>            net: phy: Reloc next and prev pointers inside phy_drivers
> > > > > >>>>>>>>>            net: phy: Fix return value check phy_probe
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> Valentin-catalin Neacsu (1):
> > > > > >>>>>>>>>            net: phy: aquantia: Set only autoneg on in register 4.c441
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> Vladimir Oltean (6):
> > > > > >>>>>>>>>            net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> > > > > >>>>>>>>>            net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> > > > > >>>>>>>>>            net: phy: ar803x: Use common functions for RGMII internal delays
> > > > > >>>>>>>>>            net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> > > > > >>>>>>>>>            net: phy: ar803x: Explicitly disable RGMII delays
> > > > > >>>>>>>>
> > > > > >>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> > > > > >>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
> > > > > >>>>>>>> AR8031/AR8033.
> > > > > >>>>>>>>
> > > > > >>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
> > > > > >>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> > > > > >>>>>>>> delay is now being disabled.
> > > > > >>>>>>>>
> > > > > >>>>>>>> Any thoughts, Vladimir?
> > > > > >>>>>>>>
> > > > > >>>>>>>> Thanks,
> > > > > >>>>>>>> -Joe
> > > > > >>>>>>>>
> > > > > >>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> > > > > >>>>>>>> [2] arch/arm/dts/am335x-evm.dts
> > > > > >>>>>>>>
> > > > > >>>>>>>>>            net: phy: ar803x: Clarify the intention of ar8021_config
> > > > > >>>>>>>>>
> > > > > >>>>>>>>>       arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> > > > > >>>>>>>>>       arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> > > > > >>>>>>>>>       arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> > > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> > > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> > > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> > > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> > > > > >>>>>>>>>       board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> > > > > >>>>>>>>>       cmd/mdio.c                                      |  27 +++--
> > > > > >>>>>>>>>       doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> > > > > >>>>>>>>>       drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> > > > > >>>>>>>>>       drivers/net/phy/Kconfig                         |  41 ++++++++
> > > > > >>>>>>>>>       drivers/net/phy/aquantia.c                      |   7 +-
> > > > > >>>>>>>>>       drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> > > > > >>>>>>>>>       drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> > > > > >>>>>>>>>       drivers/net/phy/phy.c                           |  21 +++-
> > > > > >>>>>>>>>       drivers/net/phy/realtek.c                       |  19 ++++
> > > > > >>>>>>>>>       drivers/net/phy/ti.c                            | 130 +++++-------------------
> > > > > >>>>>>>>>       include/phy.h                                   |  70 +++++++++++++
> > > > > >>>>>>>>>       19 files changed, 394 insertions(+), 221 deletions(-)
> > > > > >>>>>>>>>
> > > > > >>>>>>>>> Thanks!
> > > > > >>>>>>>>> -Joe
> > > > > >>>>>>>>> _______________________________________________
> > > > > >>>>>>>>> U-Boot mailing list
> > > > > >>>>>>>>> U-Boot@lists.denx.de
> > > > > >>>>>>>>> https://lists.denx.de/listinfo/u-boot
> > > > > >>>>>>>>
> > > > > >>>>>>>
> > > > > >>>>>>> Hi Joe, Tom,
> > > > > >>>>>>>
> > > > > >>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
> > > > > >>>>>>> causing link failure.
> > > > > >>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
> > > > > >>>>>>> correct RGMII timing budget, then for sure it was working before and now
> > > > > >>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
> > > > > >>>>>>> broken and should be corrected.
> > > > > >>>>>>> Sorry for the trouble this has caused.
> > > > > >>>>>>
> > > > > >>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
> > > > > >>>>>> there?
> > > > > >>>>>
> > > > > >>>>> On the latest net-next, it's handled the same: disable everything and
> > > > > >>>>> enable only what's specified in phy-mode. I didn't keep track of older
> > > > > >>>>> versions.
> > > > > >>>>
> > > > > >>>> So you would expect the network to be broken on net-next with this DTS?
> > > > > >>>> Because that's not allowed...
> > > > > >>>>
> > > > > >>>
> > > > > >>> Yes, if it's the same problem, the behavior should be the same.
> > > > > >>> I see net-next is only rejecting the bad DT since 2019-02-21:
> > > > > >>> https://patchwork.kernel.org/patch/10819279/
> > > > > >>> So it depends when you checked it last time.
> > > > > >>
> > > > > >> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
> > > > > >> there some work-around for the DTS so that ethernet works?
> > > > > >
> > > > > > Work-around in Linux or in U-boot?
> > > > > > U-boot can fix up the DT for Linux and replace "rgmii-txid" with
> > > > > > "rgmii-id", whereas neither Linux nor U-boot can do anything for
> > > > > > themselves except either load a correct DT blob, or not use (revert, not
> > > > > > upgrade to, etc) the enforcing patch.
> > > > > >
> > > > > >> You cannot break existing DTs
> > > > > > RGMII delay breakages happen all the time. To play the devil's advocate,
> > > > > > protecting against them should be done by observing the semantics
> > > > > > described in the devicetree/bindings document.
> > > > > > If you follow Linux net-next, a breakage for RTL8211F is planned out
> > > > > > right as we speak.
> > > > > >
> > > > > > But let's wait until we know for sure that this is what's causing the
> > > > > > issues.
> > > > > >
> > > > > > Regards,
> > > > > > -Vladimir
> > > > > >
> > > > >
> > > > > Hi Tom,
> > > > >
> > > > > I understand now what you mean by "workaround".
> > > > > Yes you can enable RGMII delays by hand in U-boot:
> > > > >
> > > > > Check if RX delay is enabled (bit 15 of debug register 0):
> > > > > => mdio write eTSEC1 0x1D 0
> > > > > => mdio read eTSEC1 0x1E
> > > > > => mdio write eTSEC1 0x1E <new value>
> > > > >
> > > > > Check if TX delay is enabled (bit 8 of debug register 5):
> > > > > => mdio write eTSEC1 0x1D 5
> > > > > => mdio read eTSEC1 0x1E
> > > > > => mdio write eTSEC1 0x1E <new value>
> > > > >
> > > > > Replace eTSEC1 with your net device from "mdio list".
> > > >
> > > > I'm not sure what the follow-on action is here. I'll hold off on
> > > > Vladimir's series until there is a resolution that everyone is
> > > > satisfied with.
> > >
> > > While I personally think this breaks the "DT is ABI" model, the required
> > > change has already been merged into Linus' tree so we just need to
> > > re-sync the am335x DTS files again and then we can apply these changes.
> > > I'll put it on my TODO list.
> >
> > Hi,
> >
> > sorry for pulling up such an old thread. Are there any news on this? Because
> > I've had the same fix for the atheros PHYs posted to the u-boot mailing list
> > lately (without knowing anything about this thread).
> >
> > So with that rule "don't break old (and very wrong!) DT blobs" we seem not
> > to be able to fix any serious errors. Because while it works for the most
> > cases eg. phy-mode = rgmii-id, it wont work (and cant be fixed!) for
> > rgmii-txid (or was it rxid? the one where the hardware default is enabled).
> >
> > I could also post my series without fixing that issue and just adding clock
> > support. But I'd rather see that fixed.
>
> So, there's patches to fix / keep cpsw working in U-Boot.  So while I
> believe that Linux broke the rule of "DT is ABI" I've also gone
> (virtually) hoarse pointing this out to the people that were supposed to
> care.  So it's on my short list to grab the changes that are needed for
> the TI platforms and we can grab all of the other changes as well.
>
> --

Tom,

How come the people who proclaim that DT is ABI (which it is, nobody
is saying otherwise) are the same as (or do it in the name of) those
who don't follow it?
Had your boards been written with the correct phy-mode in the first
place, no breakage would have happened, and maybe the Atheros PHY
driver bugs would have been caught earlier.
I agree with Michael that interpreting the "DT is ABI" phrase as "be
compatible with past mistakes" (which are not in the ABI
specification, but in its interpretation, at that!) is only going to
lead to a cacophony of incoherent interpretations, which at some point
will become impossible to reconcile.
And for U-Boot, I guess the point is moot, since the DT blob is
typically packaged with the bootloader binary anyway.

> Tom
> _______________________________________________
> U-Boot mailing list
> U-Boot@lists.denx.de
> https://lists.denx.de/listinfo/u-boot

Thanks,
-Vladimir

Tom Rini Nov. 2, 2019, 3:05 p.m. UTC | #19

On Sat, Nov 02, 2019 at 04:30:11PM +0200, Vladimir Oltean wrote:
> On Sat, 2 Nov 2019 at 16:12, Tom Rini <trini@konsulko.com> wrote:
> >
> > On Sat, Nov 02, 2019 at 02:17:28PM +0100, Michael Walle wrote:
> > > Am 2019-05-15 16:58, schrieb Tom Rini:
> > > > On Fri, May 10, 2019 at 09:50:45PM +0000, Joe Hershberger wrote:
> > > > > Hi Vladimir and Tom,
> > > > >
> > > > > On Thu, May 9, 2019 at 7:51 AM Vladimir Oltean
> > > > > <vladimir.oltean@nxp.com> wrote:
> > > > > >
> > > > > > On 09.05.2019 02:05, Vladimir Oltean wrote:
> > > > > > > On 5/9/19 1:55 AM, Tom Rini wrote:
> > > > > > >> On Wed, May 08, 2019 at 10:52:28PM +0000, Vladimir Oltean wrote:
> > > > > > >>> On 5/9/19 1:48 AM, Tom Rini wrote:
> > > > > > >>>> On Wed, May 08, 2019 at 10:45:50PM +0000, Vladimir Oltean wrote:
> > > > > > >>>>> On 5/9/19 1:42 AM, Tom Rini wrote:
> > > > > > >>>>>> On Wed, May 08, 2019 at 10:40:57PM +0000, Vladimir Oltean wrote:
> > > > > > >>>>>>> On 5/9/19 1:24 AM, Joe Hershberger wrote:
> > > > > > >>>>>>>> On Tue, May 7, 2019 at 5:15 PM Joe Hershberger <joe.hershberger@ni.com> wrote:
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> Hi Tom,
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> The following changes since commit 8d7f06bbbef16f172cd5e9c4923cdcebe16b8980:
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> I rebased on your master and built for BB Black. DHCP seems to work fine.
> > > > > > >>>>>>>>> MLO also now fits again.
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>>        Merge branch 'master' of git://git.denx.de/u-boot-sh (2019-05-07 09:38:00 -0400)
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> are available in the git repository at:
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>>        git://git.denx.de/u-boot-net.git master
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> for you to fetch changes up to 8d0c6858455e89b089222a08d55ff711681ca011:
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>>        net: phy: micrel: Find Micrel PHY node correctly (2019-05-07 14:51:55 -0500)
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> ----------------------------------------------------------------
> > > > > > >>>>>>>>> Carlo Caione (4):
> > > > > > >>>>>>>>>            net: phy: Add generic helpers to access MMD PHY registers
> > > > > > >>>>>>>>>            net: phy: ti: use generic helpers to access MMD registers
> > > > > > >>>>>>>>>            cmd: mdio: Switch to generic helpers when accessing the registers
> > > > > > >>>>>>>>>            net: phy: realtek: Introduce quirk to mark RXC not stoppable
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> James Byrne (2):
> > > > > > >>>>>>>>>            net: phy: micrel: Use correct skew values on KSZ9021
> > > > > > >>>>>>>>>            net: phy: micrel: Find Micrel PHY node correctly
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> Murali Karicheri (2):
> > > > > > >>>>>>>>>            ARM: k2g-gp-evm: update to rgmii pinmux configuration
> > > > > > >>>>>>>>>            ARM: k2g-ice: Add pinmux support for rgmii interface
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> Pankaj Bansal (1):
> > > > > > >>>>>>>>>            drivers: net: ldpaa_eth: fix resource leak
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> Siva Durga Prasad Paladugu (2):
> > > > > > >>>>>>>>>            net: phy: Reloc next and prev pointers inside phy_drivers
> > > > > > >>>>>>>>>            net: phy: Fix return value check phy_probe
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> Valentin-catalin Neacsu (1):
> > > > > > >>>>>>>>>            net: phy: aquantia: Set only autoneg on in register 4.c441
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> Vladimir Oltean (6):
> > > > > > >>>>>>>>>            net: phy: ar803x: Address packet drops at low traffic rate due to SmartEEE feature
> > > > > > >>>>>>>>>            net: phy: ar803x: Make RGMII Tx delays actually configurable for AR8035
> > > > > > >>>>>>>>>            net: phy: ar803x: Use common functions for RGMII internal delays
> > > > > > >>>>>>>>>            net: phy: ar803x: Clarify the configuration of the CLK_25M output pin
> > > > > > >>>>>>>>>            net: phy: ar803x: Explicitly disable RGMII delays
> > > > > > >>>>>>>>
> > > > > > >>>>>>>> Tom, this [1] is the patch that is breaking the evm. It doesn't affect
> > > > > > >>>>>>>> BB Black because it uses an SMSC phy, where as this evm uses an
> > > > > > >>>>>>>> AR8031/AR8033.
> > > > > > >>>>>>>>
> > > > > > >>>>>>>> Is it possible the device tree [2] is wrong for the board? It lists
> > > > > > >>>>>>>> 'phy-mode = "rgmii-txid";', so that means that with this patch the RX
> > > > > > >>>>>>>> delay is now being disabled.
> > > > > > >>>>>>>>
> > > > > > >>>>>>>> Any thoughts, Vladimir?
> > > > > > >>>>>>>>
> > > > > > >>>>>>>> Thanks,
> > > > > > >>>>>>>> -Joe
> > > > > > >>>>>>>>
> > > > > > >>>>>>>> [1] b3224e0f7e - "net: phy: ar803x: Explicitly disable RGMII delays"
> > > > > > >>>>>>>> [2] arch/arm/dts/am335x-evm.dts
> > > > > > >>>>>>>>
> > > > > > >>>>>>>>>            net: phy: ar803x: Clarify the intention of ar8021_config
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>>       arch/arm/dts/sama5d3xcm.dtsi                    |  32 +++---
> > > > > > >>>>>>>>>       arch/arm/dts/sama5d3xcm_cmp.dtsi                |  32 +++---
> > > > > > >>>>>>>>>       arch/arm/dts/socfpga_arria5_socdk.dts           |   4 +-
> > > > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_is1.dts           |   4 +-
> > > > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_socdk.dts         |   4 +-
> > > > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_sockit.dts        |   4 +-
> > > > > > >>>>>>>>>       arch/arm/dts/socfpga_cyclone5_vining_fpga.dts   |   4 +-
> > > > > > >>>>>>>>>       board/ti/ks2_evm/mux-k2g.h                      |  36 +++----
> > > > > > >>>>>>>>>       cmd/mdio.c                                      |  27 +++--
> > > > > > >>>>>>>>>       doc/device-tree-bindings/net/micrel-ksz90x1.txt |  27 +++++
> > > > > > >>>>>>>>>       drivers/net/ldpaa_eth/ldpaa_eth.c               |   1 +
> > > > > > >>>>>>>>>       drivers/net/phy/Kconfig                         |  41 ++++++++
> > > > > > >>>>>>>>>       drivers/net/phy/aquantia.c                      |   7 +-
> > > > > > >>>>>>>>>       drivers/net/phy/atheros.c                       | 128 ++++++++++++++++-------
> > > > > > >>>>>>>>>       drivers/net/phy/micrel_ksz90x1.c                |  24 ++++-
> > > > > > >>>>>>>>>       drivers/net/phy/phy.c                           |  21 +++-
> > > > > > >>>>>>>>>       drivers/net/phy/realtek.c                       |  19 ++++
> > > > > > >>>>>>>>>       drivers/net/phy/ti.c                            | 130 +++++-------------------
> > > > > > >>>>>>>>>       include/phy.h                                   |  70 +++++++++++++
> > > > > > >>>>>>>>>       19 files changed, 394 insertions(+), 221 deletions(-)
> > > > > > >>>>>>>>>
> > > > > > >>>>>>>>> Thanks!
> > > > > > >>>>>>>>> -Joe
> > > > > > >>>>>>>>> _______________________________________________
> > > > > > >>>>>>>>> U-Boot mailing list
> > > > > > >>>>>>>>> U-Boot@lists.denx.de
> > > > > > >>>>>>>>> https://lists.denx.de/listinfo/u-boot
> > > > > > >>>>>>>>
> > > > > > >>>>>>>
> > > > > > >>>>>>> Hi Joe, Tom,
> > > > > > >>>>>>>
> > > > > > >>>>>>> It sounds like what Joe pointed to (my patch) has a high chance of
> > > > > > >>>>>>> causing link failure.
> > > > > > >>>>>>> If the board is relying on RX delays in the Atheros PHY to ensure
> > > > > > >>>>>>> correct RGMII timing budget, then for sure it was working before and now
> > > > > > >>>>>>> it is broken. In that case, it was working by mistake; the DT blob is
> > > > > > >>>>>>> broken and should be corrected.
> > > > > > >>>>>>> Sorry for the trouble this has caused.
> > > > > > >>>>>>
> > > > > > >>>>>> How is this handled in the Linux kernel and/or why doesn't it fail
> > > > > > >>>>>> there?
> > > > > > >>>>>
> > > > > > >>>>> On the latest net-next, it's handled the same: disable everything and
> > > > > > >>>>> enable only what's specified in phy-mode. I didn't keep track of older
> > > > > > >>>>> versions.
> > > > > > >>>>
> > > > > > >>>> So you would expect the network to be broken on net-next with this DTS?
> > > > > > >>>> Because that's not allowed...
> > > > > > >>>>
> > > > > > >>>
> > > > > > >>> Yes, if it's the same problem, the behavior should be the same.
> > > > > > >>> I see net-next is only rejecting the bad DT since 2019-02-21:
> > > > > > >>> https://patchwork.kernel.org/patch/10819279/
> > > > > > >>> So it depends when you checked it last time.
> > > > > > >>
> > > > > > >> I'll see about testing eth in Linux with net-next tomorrow, but, uh, is
> > > > > > >> there some work-around for the DTS so that ethernet works?
> > > > > > >
> > > > > > > Work-around in Linux or in U-boot?
> > > > > > > U-boot can fix up the DT for Linux and replace "rgmii-txid" with
> > > > > > > "rgmii-id", whereas neither Linux nor U-boot can do anything for
> > > > > > > themselves except either load a correct DT blob, or not use (revert, not
> > > > > > > upgrade to, etc) the enforcing patch.
> > > > > > >
> > > > > > >> You cannot break existing DTs
> > > > > > > RGMII delay breakages happen all the time. To play the devil's advocate,
> > > > > > > protecting against them should be done by observing the semantics
> > > > > > > described in the devicetree/bindings document.
> > > > > > > If you follow Linux net-next, a breakage for RTL8211F is planned out
> > > > > > > right as we speak.
> > > > > > >
> > > > > > > But let's wait until we know for sure that this is what's causing the
> > > > > > > issues.
> > > > > > >
> > > > > > > Regards,
> > > > > > > -Vladimir
> > > > > > >
> > > > > >
> > > > > > Hi Tom,
> > > > > >
> > > > > > I understand now what you mean by "workaround".
> > > > > > Yes you can enable RGMII delays by hand in U-boot:
> > > > > >
> > > > > > Check if RX delay is enabled (bit 15 of debug register 0):
> > > > > > => mdio write eTSEC1 0x1D 0
> > > > > > => mdio read eTSEC1 0x1E
> > > > > > => mdio write eTSEC1 0x1E <new value>
> > > > > >
> > > > > > Check if TX delay is enabled (bit 8 of debug register 5):
> > > > > > => mdio write eTSEC1 0x1D 5
> > > > > > => mdio read eTSEC1 0x1E
> > > > > > => mdio write eTSEC1 0x1E <new value>
> > > > > >
> > > > > > Replace eTSEC1 with your net device from "mdio list".
> > > > >
> > > > > I'm not sure what the follow-on action is here. I'll hold off on
> > > > > Vladimir's series until there is a resolution that everyone is
> > > > > satisfied with.
> > > >
> > > > While I personally think this breaks the "DT is ABI" model, the required
> > > > change has already been merged into Linus' tree so we just need to
> > > > re-sync the am335x DTS files again and then we can apply these changes.
> > > > I'll put it on my TODO list.
> > >
> > > Hi,
> > >
> > > sorry for pulling up such an old thread. Are there any news on this? Because
> > > I've had the same fix for the atheros PHYs posted to the u-boot mailing list
> > > lately (without knowing anything about this thread).
> > >
> > > So with that rule "don't break old (and very wrong!) DT blobs" we seem not
> > > to be able to fix any serious errors. Because while it works for the most
> > > cases eg. phy-mode = rgmii-id, it wont work (and cant be fixed!) for
> > > rgmii-txid (or was it rxid? the one where the hardware default is enabled).
> > >
> > > I could also post my series without fixing that issue and just adding clock
> > > support. But I'd rather see that fixed.
> >
> > So, there's patches to fix / keep cpsw working in U-Boot.  So while I
> > believe that Linux broke the rule of "DT is ABI" I've also gone
> > (virtually) hoarse pointing this out to the people that were supposed to
> > care.  So it's on my short list to grab the changes that are needed for
> > the TI platforms and we can grab all of the other changes as well.
> >
> > --
> 
> Tom,
> 
> How come the people who proclaim that DT is ABI (which it is, nobody
> is saying otherwise) are the same as (or do it in the name of) those
> who don't follow it?

It's a good question, and I don't know why no one cared.

> Had your boards been written with the correct phy-mode in the first
> place, no breakage would have happened, and maybe the Atheros PHY
> driver bugs would have been caught earlier.

Yes, it's true that had the problem been caught 6 years ago, a lot of
things would have been better.  But it wasn't.

> I agree with Michael that interpreting the "DT is ABI" phrase as "be
> compatible with past mistakes" (which are not in the ABI
> specification, but in its interpretation, at that!) is only going to
> lead to a cacophony of incoherent interpretations, which at some point
> will become impossible to reconcile.

Part of the problem here is that I was not one of the people at the time
saying that "DT must be ABI".  I was in fact worried that there would be
a pain to fix broken DT files once they were out in the wild.  Other
people said it would be fine and that it had been done for a long while.
And that future break would be handled in a backwards compatible way.

But here we are.

> And for U-Boot, I guess the point is moot, since the DT blob is
> typically packaged with the bootloader binary anyway.

Right, so that's the whole problem.  You can't pass the old DTB to the
new kernel and have things work.  Since the example in question is an
EVM rather than shipping HW platform based on the EVM, we can say "No
one shipped the DTB embedded in to the physical HW, just pass along the
new DTB!".  I am far from convinced that there's not custom hardware
based on the EVM design and reference dts file that won't hit a problem
here when moving up.

But again, I've given up.  I say that the ABI meant that the wrong value
was supposed to work since that's what happened and a new version of the
binding needed to be used where the right value must be used.  Others
disagree.  I'm not holding U-Boot up on the new changes over this, I
just haven't put together the PR.  It's on my short list now.

Michael Walle Nov. 3, 2019, 3:22 p.m. UTC | #20

Am 2019-11-02 16:05, schrieb Tom Rini:
[snip]
> But again, I've given up.  I say that the ABI meant that the wrong 
> value
> was supposed to work since that's what happened and a new version of 
> the
> binding needed to be used where the right value must be used.  Others
> disagree.  I'm not holding U-Boot up on the new changes over this, I
> just haven't put together the PR.  It's on my short list now.

I want to rebase my cleanup and device tree support for the Atheros PHY 
onto the patches by Vladimir. Although I do have some problems/questions 
now:

  - will the whole series [1] be pulled altogether?
  - there is a kconfig option to control the EEE option. Wouldn't it be 
better to put that into a device tree property option too?
  - there were some cleanups I'd do another way, for example the clock 
enumeration uses "BIT(0) | BIT(1)" instead of 3. I'd use a mask and the 
correct enumeration and FIELD_PREP(). So should I base my patch on 
Vladimirs patch? Should Vladimir post a new patch?

To be frank, I'd rather pull Vladimirs patches and change (or drop them 
if they are superseeded mine), if everyone is ok with that. I'd propose 
the following:
  - I rebase my patches onto Vladimirs patches
  - change some of Vladimirs patches
  - privately, mail the patch series to Vladimir, then he can review 
them, add SOB or other tags
  - If he is ok with the changes, I'll post another "atheros PHY cleanup 
and device tree support" series with patches from Vladimir and myself.

I don't really want to hijack any patches, but patching the patch seems 
to be not really good.

Does anybody know if the "disable smartEEE" should go into the linux phy 
driver too? As far as I understand it, linux configures the complete phy 
itself, (eg. it might even do a hardware reset).

[U-Boot] Pull request: u-boot-net.git master

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