| Message ID | 20230224000400.12226-4-zev@bewilderbeest.net |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | ARM: dts: aspeed: ASRock BMC updates | expand |
On Fri, 24 Feb 2023 at 00:04, Zev Weiss <zev@bewilderbeest.net> wrote: > > While I'm not aware of any problems that have occurred running these > at 100 MHz, the official word from ASRock is that 50 MHz is the > correct speed to use, so let's be safe and use that instead. :( Validated with which driver? Cédric, do you have any thoughts on this? > > Signed-off-by: Zev Weiss <zev@bewilderbeest.net> > Cc: stable@vger.kernel.org > Fixes: 2b81613ce417 ("ARM: dts: aspeed: Add ASRock E3C246D4I BMC") > Fixes: a9a3d60b937a ("ARM: dts: aspeed: Add ASRock ROMED8HM3 BMC") > --- > arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts | 2 +- > arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts b/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts > index 67a75aeafc2b..c4b2efbfdf56 100644 > --- a/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts > +++ b/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts > @@ -63,7 +63,7 @@ flash@0 { > status = "okay"; > m25p,fast-read; > label = "bmc"; > - spi-max-frequency = <100000000>; /* 100 MHz */ > + spi-max-frequency = <50000000>; /* 50 MHz */ > #include "openbmc-flash-layout.dtsi" > }; > }; > diff --git a/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts b/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts > index 00efe1a93a69..4554abf0c7cd 100644 > --- a/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts > +++ b/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts > @@ -51,7 +51,7 @@ flash@0 { > status = "okay"; > m25p,fast-read; > label = "bmc"; > - spi-max-frequency = <100000000>; /* 100 MHz */ > + spi-max-frequency = <50000000>; /* 50 MHz */ > #include "openbmc-flash-layout-64.dtsi" > }; > }; > -- > 2.39.1.438.gdcb075ea9396.dirty >
On 3/1/23 02:30, Joel Stanley wrote: > On Fri, 24 Feb 2023 at 00:04, Zev Weiss <zev@bewilderbeest.net> wrote: >> >> While I'm not aware of any problems that have occurred running these >> at 100 MHz, the official word from ASRock is that 50 MHz is the >> correct speed to use, so let's be safe and use that instead. > > :( > > Validated with which driver? > > Cédric, do you have any thoughts on this? Transactions on the Firmware SPI controller are usually configured at 50MHz by U-Boot and Linux to stay on the safe side, specially CE0 from which the board boots. The other SPI controllers are generally set at a higher freq : 100MHz, because the devices on these buses are not for booting the BMC, they are mostly only written to (at a default lower freq). There are some exceptions when the devices and the wiring permit higher rates. For the record, we lowered the SPI freq on the AST2400 (palmetto) because some chips would freak out once in a while at 100MHz. C. >> Signed-off-by: Zev Weiss <zev@bewilderbeest.net> >> Cc: stable@vger.kernel.org >> Fixes: 2b81613ce417 ("ARM: dts: aspeed: Add ASRock E3C246D4I BMC") >> Fixes: a9a3d60b937a ("ARM: dts: aspeed: Add ASRock ROMED8HM3 BMC") >> --- >> arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts | 2 +- >> arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts b/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts >> index 67a75aeafc2b..c4b2efbfdf56 100644 >> --- a/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts >> +++ b/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts >> @@ -63,7 +63,7 @@ flash@0 { >> status = "okay"; >> m25p,fast-read; >> label = "bmc"; >> - spi-max-frequency = <100000000>; /* 100 MHz */ >> + spi-max-frequency = <50000000>; /* 50 MHz */ >> #include "openbmc-flash-layout.dtsi" >> }; >> }; >> diff --git a/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts b/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts >> index 00efe1a93a69..4554abf0c7cd 100644 >> --- a/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts >> +++ b/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts >> @@ -51,7 +51,7 @@ flash@0 { >> status = "okay"; >> m25p,fast-read; >> label = "bmc"; >> - spi-max-frequency = <100000000>; /* 100 MHz */ >> + spi-max-frequency = <50000000>; /* 50 MHz */ >> #include "openbmc-flash-layout-64.dtsi" >> }; >> }; >> -- >> 2.39.1.438.gdcb075ea9396.dirty >>
On Tue, Feb 28, 2023 at 11:33:58PM PST, Cédric Le Goater wrote: >On 3/1/23 02:30, Joel Stanley wrote: >>On Fri, 24 Feb 2023 at 00:04, Zev Weiss <zev@bewilderbeest.net> wrote: >>> >>>While I'm not aware of any problems that have occurred running these >>>at 100 MHz, the official word from ASRock is that 50 MHz is the >>>correct speed to use, so let's be safe and use that instead. >> >>:( >> >>Validated with which driver? >> spi-nor, FWIW. >>Cédric, do you have any thoughts on this? > >Transactions on the Firmware SPI controller are usually configured at >50MHz by U-Boot and Linux to stay on the safe side, specially CE0 from >which the board boots. The other SPI controllers are generally set at >a higher freq : 100MHz, because the devices on these buses are not for >booting the BMC, they are mostly only written to (at a default lower >freq). There are some exceptions when the devices and the wiring permit >higher rates. > >For the record, we lowered the SPI freq on the AST2400 (palmetto) >because some chips would freak out once in a while at 100MHz. > >C. > Yeah, this actually grew out of some OpenBMC bringup work on another ASRock board -- I started out with a 100MHz clock since that's what I'd been using without a hitch on previous ASRock systems (such as these), but saw sporadic data corruption. Some discussion on the OpenBMC Discord (https://discord.com/channels/775381525260664832/775694683589574659/1074904879023263774 and https://discord.com/channels/775381525260664832/775694683589574659/1075336116212875335) prompted me to try 50MHz instead, which seemed to solve the problem -- then after enquiring about it with ASRock I discovered that the 100MHz clocks we've been using on these boards are also officially out of spec. Zev
diff --git a/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts b/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts index 67a75aeafc2b..c4b2efbfdf56 100644 --- a/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts +++ b/arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts @@ -63,7 +63,7 @@ flash@0 { status = "okay"; m25p,fast-read; label = "bmc"; - spi-max-frequency = <100000000>; /* 100 MHz */ + spi-max-frequency = <50000000>; /* 50 MHz */ #include "openbmc-flash-layout.dtsi" }; }; diff --git a/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts b/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts index 00efe1a93a69..4554abf0c7cd 100644 --- a/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts +++ b/arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts @@ -51,7 +51,7 @@ flash@0 { status = "okay"; m25p,fast-read; label = "bmc"; - spi-max-frequency = <100000000>; /* 100 MHz */ + spi-max-frequency = <50000000>; /* 50 MHz */ #include "openbmc-flash-layout-64.dtsi" }; };
While I'm not aware of any problems that have occurred running these at 100 MHz, the official word from ASRock is that 50 MHz is the correct speed to use, so let's be safe and use that instead. Signed-off-by: Zev Weiss <zev@bewilderbeest.net> Cc: stable@vger.kernel.org Fixes: 2b81613ce417 ("ARM: dts: aspeed: Add ASRock E3C246D4I BMC") Fixes: a9a3d60b937a ("ARM: dts: aspeed: Add ASRock ROMED8HM3 BMC") --- arch/arm/boot/dts/aspeed-bmc-asrock-e3c246d4i.dts | 2 +- arch/arm/boot/dts/aspeed-bmc-asrock-romed8hm3.dts | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)