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

[Daniele Ceraolo Spurio]

On 8/7/2024 3:42 PM, 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.

ok, will switch.

>
> 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. patch 2 in this series extends the WA to BMG (will rework that as 
well to use the GRAPHICS_VERSION).

Daniele

>
> 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
>>>