[Intel-xe] [PATCH 4/7] drm/xe: Fix Wa_22011802037 annotation

[Lucas De Marchi]

On Thu, May 04, 2023 at 12:15:54PM -0400, Rodrigo Vivi wrote:
>On Thu, May 04, 2023 at 12:32:47AM -0700, Lucas De Marchi wrote:
>> It was missing one digit, so not showing up as a proper WA number. Add
>> the missing number and annotate it with a FIXME as there are more to be
>> implemented to consider this WA done: ensure CS is stop before doing a
>> reset, wait for pending.
>>
>> Also, this WA applies to platforms up to graphics version 1270 (with the
>> exception of MTL A*, that are not supported in xe). Fix platform check.
>>
>> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>> ---
>>  drivers/gpu/drm/xe/xe_guc.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
>> index 62b4fcf84acf..f7d32b744247 100644
>> --- a/drivers/gpu/drm/xe/xe_guc.c
>> +++ b/drivers/gpu/drm/xe/xe_guc.c
>> @@ -162,9 +162,11 @@ static u32 guc_ctl_wa_flags(struct xe_guc *guc)
>>  		flags |= GUC_WA_DUAL_QUEUE;
>>
>>  	/*
>> -	 * Wa_2201180203
>> +	 * Wa_22011802037:
>
>nice catch!
>
>> FIXME - there's more to be done than simply setting
>> +	 * this flag: make sure each CS is stopped when preparing for GT reset
>> +	 * and wait for pending MI_FW.
>
>ouch, we need this! Or maybe GuC is doing this for us if we we pass the flag?

GuC is not doing it for us, no. This is for driver-initiated GT reset
and it's the driver responsibility to do this.  The prepare_reset hook
afaics is already in place, however the loop over all engines stopping
the CSs and ensuring we wait for the MI_FW are not. And from a quick
look in i915 doesn't seem very trivial amount of code to add in this
series.

>
>>  	 */
>> -	if (GRAPHICS_VER(xe) <= 12)
>> +	if (GRAPHICS_VERx100(xe) < 1270)
>
>We need this in all the platforms including TGL from what I can see...
>Why are you limiting it?

we don't need it on MTL. `GRAPHICS_VERx100(xe) < 1270` includes all
platforms before MTL.

Lucas De Marchi