[PATCH] drm/xe: Merge 16021540221 and 18034896535 WAs

[Lucas De Marchi]

On Mon, Apr 29, 2024 at 09:14:30AM GMT, Chauhan, Shekhar wrote:
>
>On 4/27/2024 19:23, Lucas De Marchi wrote:
>>In order to detect duplicate implementations for the same workaround,
>>early in the implementation of RTP it was decided to error out even if
>>the values set are exactly the same. With the introduction of 18034896535
>>in commit 74671d23ca18 ("drm/xe/xe2: Add workaround 18034896535"), LNL
>>stepping with graphics stepping A1 now gives the following error on
>>module load:
>>
>>	xe 0000:00:02.0: [drm] *ERROR* GT0: [GT OTHER] \
>>	discarding save-restore reg e48c (clear: 00000200, set: 00000200,\
>>	masked: yes, mcr: yes): ret=-22
>>
>>RTP may be improved in the future, but for now simply join the entries
>>like done with e.g. "1607297627, 1607030317, 1607186500".
>>
>>Fixes: 74671d23ca18 ("drm/xe/xe2: Add workaround 18034896535")
>>Cc: Bommu Krishnaiah <krishnaiah.bommu at intel.com>
>>Cc: Tejas Upadhyay <tejas.upadhyay at intel.com>
>>Cc: Matt Roper <matthew.d.roper at intel.com>
>>Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>>---
>>  drivers/gpu/drm/xe/xe_wa.c | 7 +------
>>  1 file changed, 1 insertion(+), 6 deletions(-)
>>
>>diff --git a/drivers/gpu/drm/xe/xe_wa.c b/drivers/gpu/drm/xe/xe_wa.c
>>index 9d9b7fa7a8f0..db7c7c7875c5 100644
>>--- a/drivers/gpu/drm/xe/xe_wa.c
>>+++ b/drivers/gpu/drm/xe/xe_wa.c
>>@@ -449,12 +449,7 @@ 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("16021540221"),
>>-	  XE_RTP_RULES(GRAPHICS_VERSION(2004), GRAPHICS_STEP(A0, B0),
>>-		       FUNC(xe_rtp_match_first_render_or_compute)),
>>-	  XE_RTP_ACTIONS(SET(ROW_CHICKEN4, DISABLE_TDL_PUSH))
>>-	},
>>-	{ XE_RTP_NAME("18034896535"),
>>+	{ XE_RTP_NAME("18034896535, 16021540221"), /* 16021540221: GRAPHICS_STEP(A0, B0) */
>>  	  XE_RTP_RULES(GRAPHICS_VERSION_RANGE(2001, 2004),
>
>w/a 16021540221 is applicable to only Steppings A0 to B0 (B0 not 
>inclusive). With your change, I think the w/a will be applied to all 
>the steppings. Wouldn't this be incorrect? Please provide some 
>guidance.

both 18034896535 and 16021540221 have the same action:

	SET(ROW_CHICKEN4, DISABLE_TDL_PUSH)

In other words, 18034896535 applies to a superset of platforms
16021540221 applies to. So even when we remove support for steppings A*,
we want to keep the WA (possibly removing the comment about 16021540221
and renaming it).

Lucas De Marchi

>
>>  		       FUNC(xe_rtp_match_first_render_or_compute)),
>>  	  XE_RTP_ACTIONS(SET(ROW_CHICKEN4, DISABLE_TDL_PUSH))
>
>-- 
>-shekhar
>