[PATCH v2 2/3] drm/xe/xe2_hpg: Add set of workarounds

[Lucas De Marchi]

On Wed, Jun 04, 2025 at 11:54:19AM -0700, Matt Roper wrote:
>On Wed, Jun 04, 2025 at 08:22:35PM +0530, Dnyaneshwar Bhadane wrote:
>> From: Shekhar Chauhan <shekhar.chauhan at intel.com>
>>
>> Add set of workarounds for xe2_hpg.
>>
>> -v2: Fix xe2_hpg GMD version for some workarounds.
>>
>> Signed-off-by: Shekhar Chauhan <shekhar.chauhan at intel.com>
>> Signed-off-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane at intel.com>
>> ---
>>  drivers/gpu/drm/xe/xe_wa.c         | 55 +++++++++++++++++++++---------
>>  drivers/gpu/drm/xe/xe_wa_oob.rules |  4 +--
>>  2 files changed, 40 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_wa.c b/drivers/gpu/drm/xe/xe_wa.c
>> index 67196baa4249..2c0e0adc5904 100644
>> --- a/drivers/gpu/drm/xe/xe_wa.c
>> +++ b/drivers/gpu/drm/xe/xe_wa.c
>> @@ -489,8 +489,8 @@ static const struct xe_rtp_entry_sr engine_was[] = {
>>  	  XE_RTP_RULES(GRAPHICS_VERSION(2004), FUNC(xe_rtp_match_first_render_or_compute)),
>>  	  XE_RTP_ACTIONS(SET(ROW_CHICKEN3, XE2_EUPEND_CHK_FLUSH_DIS))
>>  	},
>> -	{ XE_RTP_NAME("18034896535, 16021540221"), /* 16021540221: GRAPHICS_STEP(A0, B0) */
>> -	  XE_RTP_RULES(GRAPHICS_VERSION_RANGE(2001, 2004),
>> +	{ XE_RTP_NAME("16021540221"),
>> +	  XE_RTP_RULES(GRAPHICS_VERSION(2004), GRAPHICS_STEP(A0, B0),
>
>Breaking out 20.01/20.02 into a separate entry farther down is good
>since it keeps the LPG and HPG handling separate, and also avoids
>blindly applying this 20.03 which doesn't exist today, but could
>potentially show up in the future.
>
>However is there actually a benefit to splitting 16021540221 (a-step
>only) and 18034896535 (all steppings) into separate entries given that
>the two workarounds have the same actions?  I think breaking it out like
>this will actually cause a warning if run on an A-step platform since
>we'll have two entries trying to update the same bits of the same
>register (see compatible_entries() in xe_reg_sr.c).

humn... it looks like our kunit in drivers/gpu/drm/xe/tests/xe_wa_test.c
is only covering the gt table, not engine. We should add entries for

	KUNIT_CASE_PARAM(xe_wa_engine, platform_gen_params),

and

	KUNIT_CASE_PARAM(xe_wa_lrc, platform_gen_params),

to cover this in kunit and avoid introducing these bugs.
Shekhar/Dnyaneshwar, would you be able to do that? It can (should?) be
separate from these patches to avoid unnecessary delays in applying
these workarounds.

thanks
Lucas De Marchi