[PATCH] platform/x86: amd-pmc: Increase the response register timeout

[PATCH] platform/x86: amd-pmc: Increase the response register timeout

[Mario Limonciello]

There have been reports of approximately a 0.9%-1.7% failure rate in SMU
communication timeouts with s0i3 entry on some OEM designs.  Currently
the design in amd-pmc is to try every 100us for up to 20ms.

However the GPU driver which also communicates with the SMU using a
mailbox register which the driver polls every 1us for up to 2000ms.
In the GPU driver this was increased by commit 055162645a40 ("drm/amd/pm:
increase time out value when sending msg to SMU")

Increase the maximum timeout used by amd-pmc to 2000ms to match this
behavior.  This has been shown to improve the stability for machines
that randomly have failures.

Cc: stable@kernel.org
Reported-by: Julian Sikorski <belegdol@gmail.com>
BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1629
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/platform/x86/amd-pmc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
index 3481479a2942..d6a7c896ac86 100644
--- a/drivers/platform/x86/amd-pmc.c
+++ b/drivers/platform/x86/amd-pmc.c
@@ -71,7 +71,7 @@
 #define AMD_CPU_ID_YC			0x14B5
 
 #define PMC_MSG_DELAY_MIN_US		100
-#define RESPONSE_REGISTER_LOOP_MAX	200
+#define RESPONSE_REGISTER_LOOP_MAX	20000
 
 #define SOC_SUBSYSTEM_IP_MAX	12
 #define DELAY_MIN_US		2000
-- 
2.25.1

Re: [PATCH] platform/x86: amd-pmc: Increase the response register timeout

[Shyam Sundar S K]

On 9/14/2021 7:31 AM, Mario Limonciello wrote:
> There have been reports of approximately a 0.9%-1.7% failure rate in SMU
> communication timeouts with s0i3 entry on some OEM designs.  Currently
> the design in amd-pmc is to try every 100us for up to 20ms.
> 
> However the GPU driver which also communicates with the SMU using a
> mailbox register which the driver polls every 1us for up to 2000ms.
> In the GPU driver this was increased by commit 055162645a40 ("drm/amd/pm:
> increase time out value when sending msg to SMU")
> 
> Increase the maximum timeout used by amd-pmc to 2000ms to match this
> behavior.  This has been shown to improve the stability for machines
> that randomly have failures.
> 
> Cc: stable@kernel.org
> Reported-by: Julian Sikorski <belegdol@gmail.com>
> BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1629
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/platform/x86/amd-pmc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
> index 3481479a2942..d6a7c896ac86 100644
> --- a/drivers/platform/x86/amd-pmc.c
> +++ b/drivers/platform/x86/amd-pmc.c
> @@ -71,7 +71,7 @@
>  #define AMD_CPU_ID_YC			0x14B5
>  
>  #define PMC_MSG_DELAY_MIN_US		100
> -#define RESPONSE_REGISTER_LOOP_MAX	200
> +#define RESPONSE_REGISTER_LOOP_MAX	20000
>  
>  #define SOC_SUBSYSTEM_IP_MAX	12
>  #define DELAY_MIN_US		2000
> 

Looks good to me.

Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>

Re: [PATCH] platform/x86: amd-pmc: Increase the response register timeout

[Hans de Goede]

Hi,

On 9/14/21 10:38 AM, Shyam Sundar S K wrote:
> 
> 
> On 9/14/2021 7:31 AM, Mario Limonciello wrote:
>> There have been reports of approximately a 0.9%-1.7% failure rate in SMU
>> communication timeouts with s0i3 entry on some OEM designs.  Currently
>> the design in amd-pmc is to try every 100us for up to 20ms.
>>
>> However the GPU driver which also communicates with the SMU using a
>> mailbox register which the driver polls every 1us for up to 2000ms.
>> In the GPU driver this was increased by commit 055162645a40 ("drm/amd/pm:
>> increase time out value when sending msg to SMU")
>>
>> Increase the maximum timeout used by amd-pmc to 2000ms to match this
>> behavior.  This has been shown to improve the stability for machines
>> that randomly have failures.
>>
>> Cc: stable@kernel.org
>> Reported-by: Julian Sikorski <belegdol@gmail.com>
>> BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1629
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
>>  drivers/platform/x86/amd-pmc.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
>> index 3481479a2942..d6a7c896ac86 100644
>> --- a/drivers/platform/x86/amd-pmc.c
>> +++ b/drivers/platform/x86/amd-pmc.c
>> @@ -71,7 +71,7 @@
>>  #define AMD_CPU_ID_YC			0x14B5
>>  
>>  #define PMC_MSG_DELAY_MIN_US		100
>> -#define RESPONSE_REGISTER_LOOP_MAX	200
>> +#define RESPONSE_REGISTER_LOOP_MAX	20000
>>  
>>  #define SOC_SUBSYSTEM_IP_MAX	12
>>  #define DELAY_MIN_US		2000
>>
> 
> Looks good to me.
> 
> Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>

Thank you for your patch, I've applied this patch to my review-hans 
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

I've also added this to the fixes branch so that it will be included
when I send my next fixes for 5.15 pull-req to Linus.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans