diff mbox

[U-Boot,v5,1/3] net: phy: Optionally force master mode for RTL PHY

Message ID 1458926572-21236-2-git-send-email-haas@computerlinguist.org
State Accepted
Commit 525d187afb418a4deef8916844f5f7744da402a8
Delegated to: Hans de Goede
Headers show

Commit Message

Michael Haas March 25, 2016, 5:22 p.m. UTC
This patch introduces CONFIG_RTL8211X_PHY_FORCE_MASTER. If this
define is set, RTL8211x PHYs (except for the RTL8211F) will have their
1000BASE-T master/slave autonegotiation disabled and forced to master
mode.

This is helpful for PHYs like the RTL8211C which produce unstable links
in slave mode. Such problems have been found on the A20-Olimex-SOM-EVB
and A20-OLinuXino-Lime2.

There is no proper way to identify affected PHYs in software as the
RTL8211C shares its UID with the RTL8211B. Thus, this fix requires
the introduction of an #ifdef.

CC: fradav@gmail.com
CC: merker@debian.org
CC: hdegoede@redhat.com
CC: ijc@hellion.org.uk
CC: joe.hershberger@ni.com

Signed-off-by: Michael Haas <haas@computerlinguist.org>
Tested-by: Karsten Merker <merker@debian.org>

---

Changes in v5:
 - Improve formatting of Kconfig help text. No content change. Change
   suggested by Karsten Merker.

Changes in v4:
 - Squashed previously separate commit introducing KCONFIG variable
   into commit containing main code change (Hans de Goede's suggestion)
 - Changed KCONFIG description according to Karsten Merker's suggestions
   plus some clarification of my own
 - Changed commit message according to Karsten Merker's suggestions

Changes in v3:
 - Remove incorrect detection of RTL8211CL and use #ifdef instead
   (thanks to Karsten Merker)
 - Introduced constants for register bits

Changes in v2:
 - Removed accidental inclusion of Karsten's patch in my first submission of this series.
 - Fix a typo in the code: 6 -> &

 drivers/net/Kconfig       | 21 +++++++++++++++++++++
 drivers/net/phy/realtek.c | 13 ++++++++++++-
 2 files changed, 33 insertions(+), 1 deletion(-)

Comments

Joe Hershberger March 25, 2016, 9:11 p.m. UTC | #1
On Fri, Mar 25, 2016 at 12:22 PM, Michael Haas
<haas@computerlinguist.org> wrote:
> This patch introduces CONFIG_RTL8211X_PHY_FORCE_MASTER. If this
> define is set, RTL8211x PHYs (except for the RTL8211F) will have their
> 1000BASE-T master/slave autonegotiation disabled and forced to master
> mode.
>
> This is helpful for PHYs like the RTL8211C which produce unstable links
> in slave mode. Such problems have been found on the A20-Olimex-SOM-EVB
> and A20-OLinuXino-Lime2.
>
> There is no proper way to identify affected PHYs in software as the
> RTL8211C shares its UID with the RTL8211B. Thus, this fix requires
> the introduction of an #ifdef.
>
> CC: fradav@gmail.com
> CC: merker@debian.org
> CC: hdegoede@redhat.com
> CC: ijc@hellion.org.uk
> CC: joe.hershberger@ni.com
>
> Signed-off-by: Michael Haas <haas@computerlinguist.org>
> Tested-by: Karsten Merker <merker@debian.org>

Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Hans de Goede March 28, 2016, 12:54 p.m. UTC | #2
Hi,

On 25-03-16 22:11, Joe Hershberger wrote:
> On Fri, Mar 25, 2016 at 12:22 PM, Michael Haas
> <haas@computerlinguist.org> wrote:
>> This patch introduces CONFIG_RTL8211X_PHY_FORCE_MASTER. If this
>> define is set, RTL8211x PHYs (except for the RTL8211F) will have their
>> 1000BASE-T master/slave autonegotiation disabled and forced to master
>> mode.
>>
>> This is helpful for PHYs like the RTL8211C which produce unstable links
>> in slave mode. Such problems have been found on the A20-Olimex-SOM-EVB
>> and A20-OLinuXino-Lime2.
>>
>> There is no proper way to identify affected PHYs in software as the
>> RTL8211C shares its UID with the RTL8211B. Thus, this fix requires
>> the introduction of an #ifdef.
>>
>> CC: fradav@gmail.com
>> CC: merker@debian.org
>> CC: hdegoede@redhat.com
>> CC: ijc@hellion.org.uk
>> CC: joe.hershberger@ni.com
>>
>> Signed-off-by: Michael Haas <haas@computerlinguist.org>
>> Tested-by: Karsten Merker <merker@debian.org>
>
> Acked-by: Joe Hershberger <joe.hershberger@ni.com>

Series looks good to me:

Acked-by: Hans de Goede <hdegoede@redhat.com>

Joe, how do you want to proceed with upstreaming this, shall I take
all 3 patches upstream through u-boot-sunxi ?

Regards,

Hans
Joe Hershberger March 28, 2016, 4:12 p.m. UTC | #3
Hi Hans,

On Mon, Mar 28, 2016 at 7:54 AM, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
>
> On 25-03-16 22:11, Joe Hershberger wrote:
>>
>> On Fri, Mar 25, 2016 at 12:22 PM, Michael Haas
>> <haas@computerlinguist.org> wrote:
>>>
>>> This patch introduces CONFIG_RTL8211X_PHY_FORCE_MASTER. If this
>>> define is set, RTL8211x PHYs (except for the RTL8211F) will have their
>>> 1000BASE-T master/slave autonegotiation disabled and forced to master
>>> mode.
>>>
>>> This is helpful for PHYs like the RTL8211C which produce unstable links
>>> in slave mode. Such problems have been found on the A20-Olimex-SOM-EVB
>>> and A20-OLinuXino-Lime2.
>>>
>>> There is no proper way to identify affected PHYs in software as the
>>> RTL8211C shares its UID with the RTL8211B. Thus, this fix requires
>>> the introduction of an #ifdef.
>>>
>>> CC: fradav@gmail.com
>>> CC: merker@debian.org
>>> CC: hdegoede@redhat.com
>>> CC: ijc@hellion.org.uk
>>> CC: joe.hershberger@ni.com
>>>
>>> Signed-off-by: Michael Haas <haas@computerlinguist.org>
>>> Tested-by: Karsten Merker <merker@debian.org>
>>
>>
>> Acked-by: Joe Hershberger <joe.hershberger@ni.com>
>
>
> Series looks good to me:
>
> Acked-by: Hans de Goede <hdegoede@redhat.com>
>
> Joe, how do you want to proceed with upstreaming this, shall I take
> all 3 patches upstream through u-boot-sunxi ?

Sounds good to me.

-Joe
diff mbox

Patch

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 2a229b8..e0008fd 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -13,6 +13,27 @@  config PHYLIB
 	help
 	  Enable Ethernet PHY (physical media interface) support.
 
+config RTL8211X_PHY_FORCE_MASTER
+	bool "Ethernet PHY RTL8211x: force 1000BASE-T master mode"
+	depends on PHYLIB
+	help
+	  Force master mode for 1000BASE-T on RTl8211x PHYs (except for RTL8211F).
+	  This can work around link stability and data corruption issues on gigabit
+	  links which can occur in slave mode on certain PHYs, e.g. on the
+	  RTL8211C(L).
+
+	  Please note that two directly connected devices (i.e. via crossover cable)
+	  will not be able to establish a link between each other if they both force
+	  master mode. Multiple devices forcing master mode when connected by a
+	  network switch do not pose a problem as the switch configures its affected
+	  ports into slave mode.
+
+	  This option only affects gigabit links. If you must establish a direct
+	  connection between two devices which both force master mode, try forcing
+	  the link speed to 100MBit/s.
+
+	  If unsure, say N.
+
 menuconfig NETDEVICES
 	bool "Network device support"
 	depends on NET
diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index 259a87f..359ec50 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -12,6 +12,10 @@ 
 
 #define PHY_AUTONEGOTIATE_TIMEOUT 5000
 
+/* RTL8211x 1000BASE-T Control Register */
+#define MIIM_RTL8211x_CTRL1000T_MSCE (1 << 12);
+#define MIIM_RTL8211X_CTRL1000T_MASTER (1 << 11);
+
 /* RTL8211x PHY Status Register */
 #define MIIM_RTL8211x_PHY_STATUS       0x11
 #define MIIM_RTL8211x_PHYSTAT_SPEED    0xc000
@@ -53,7 +57,14 @@  static int rtl8211x_config(struct phy_device *phydev)
 	 */
 	phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211x_PHY_INER,
 		  MIIM_RTL8211x_PHY_INTR_DIS);
-
+#ifdef CONFIG_RTL8211X_PHY_FORCE_MASTER
+	unsigned int reg = phy_read(phydev, MDIO_DEVAD_NONE, MII_CTRL1000);
+	/* force manual master/slave configuration */
+	reg |= MIIM_RTL8211x_CTRL1000T_MSCE;
+	/* force master mode */
+	reg |= MIIM_RTL8211X_CTRL1000T_MASTER;
+	phy_write(phydev, MDIO_DEVAD_NONE, MII_CTRL1000, reg);
+#endif
 	/* read interrupt status just to clear it */
 	phy_read(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211x_PHY_INER);