[PATCH 1/2] drm/xe: fix WA 14018094691

[Lucas De Marchi]

On Wed, Aug 07, 2024 at 03:42:09PM GMT, Matt Roper wrote:
>On Wed, Aug 07, 2024 at 04:51:32PM -0500, Lucas De Marchi wrote:
>> On Wed, Aug 07, 2024 at 02:11:05PM GMT, Daniele Ceraolo Spurio wrote:
>> > This WA is applied while initializing the media GT, but it is currently
>> > defined as a primary GT WA (because it modifies a register on the
>> > primary GT), so the XE_WA macro is returning false even when the WA
>> > should be applied.
>>
>> humn... I don't see the media gt marked in the WA db. Does it need to
>> be updated considering the GSC is actually loaded in the media GT? But
>> it would be odd to write to the primary_gt. So... alternative approach
>> that I think would be more correct would be to change the implementation
>> in drivers/gpu/drm/xe/xe_gsc.c so it passes the primary_gt to XE_WA(),
>> just like it's doing when writing the register.
>>
>> Thoughts? Would also like to see Matt Roper's opinion
>
>Yeah, I agree.  It sounds like the workaround applicability is keyed off
>the primary GT's IP and the registers that need to be written are also
>the primary GT's copy, so I think we should just be passing that GT to
>XE_WA() as well.
>
>BTW, it looks like this workaround needs to apply to both graphics
>version 20.04 (used by LNL) and 20.01 (used by BMG) if I'm reading
>correctly?

yes, it's the second patch in this series.


Lucas De Marchi

>
>
>Matt
>
>>
>> Lucas De Marchi
>>
>> > Since both GTs are involved in the flow, fix this by marking the WA as
>> > applying to the platform instead of just the specific GT.
>> >
>> > Note that this WA only applies to PXP and we don't yet support that in
>> > Xe, so there are no negative effects to this bug, which is why we didn't
>> > see any errors in testing.
>> >
>> > Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
>> > Cc: Matt Roper <matthew.d.roper at intel.com>
>> > ---
>> > drivers/gpu/drm/xe/xe_wa_oob.rules | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/gpu/drm/xe/xe_wa_oob.rules b/drivers/gpu/drm/xe/xe_wa_oob.rules
>> > index 540d38603f32..40354fb01737 100644
>> > --- a/drivers/gpu/drm/xe/xe_wa_oob.rules
>> > +++ b/drivers/gpu/drm/xe/xe_wa_oob.rules
>> > @@ -19,7 +19,7 @@
>> > 		GRAPHICS_VERSION_RANGE(1270, 1274)
>> > 		MEDIA_VERSION(1300)
>> > 		PLATFORM(DG2)
>> > -14018094691	GRAPHICS_VERSION(2004)
>> > +14018094691	PLATFORM(LUNARLAKE)
>> > 14019882105	GRAPHICS_VERSION(2004), GRAPHICS_STEP(A0, B0)
>> > 18024947630	GRAPHICS_VERSION(2001)
>> > 		GRAPHICS_VERSION(2004)
>> > --
>> > 2.43.0
>> >
>
>-- 
>Matt Roper
>Graphics Software Engineer
>Linux GPU Platform Enablement
>Intel Corporation