On Mon, May 15, 2023 at 03:24:23PM -0700, Radhakrishna Sripada wrote:
> The dg2 workaround which requires the register for
> DRAW_WATERMARK to be saved/restored during context reset/switch
> is required on MTL-A step as well.
Maybe it would be more clear if this was written as
Like DG2, MTL a-step hardware is subject to Wa_16014892111 which
requires that the any changes made to the DRAW_WATERMARK
register be done via an INDIRECT_CTX batch buffer rather than
through a regular context workaround.
The bspec gives the same non-default recommended tuning value
for DRAW_WATERMARK as DG2, so we can re-use the the INDIRECT_CTX
code to apply that tuning setting on A-step hardware.
Application of the tuning setting on B-step and later does not
need INDIRECT_CTX handling and is already done in
mtl_ctx_workarounds_init() as usual.
>
> v2: Limit the WA for A-step
> v3: Update the commit message.
>
> Bspec: 68331
> Cc: Haridhar Kalvala <haridhar.kalvala@xxxxxxxxx>
> Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
> Cc: Gustavo Sousa <gustavo.sousa@xxxxxxxxx>
> Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_lrc.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index 81a96c52a92b..9c1007c44298 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -1370,7 +1370,9 @@ gen12_emit_indirect_ctx_rcs(const struct intel_context *ce, u32 *cs)
> cs, GEN12_GFX_CCS_AUX_NV);
>
> /* Wa_16014892111 */
> - if (IS_DG2(ce->engine->i915))
> + if (IS_DG2(ce->engine->i915) ||
> + IS_MTL_GRAPHICS_STEP(ce->engine->i915, M, STEP_A0, STEP_B0) ||
> + IS_MTL_GRAPHICS_STEP(ce->engine->i915, P, STEP_A0, STEP_B0))
As with the previous patch, it would be best to put the newest platform
first in the 'if' statement. Aside from that (and the commit message
clarification above),
Reviewed-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
Matt
> cs = dg2_emit_draw_watermark_setting(cs);
>
> return cs;
> --
> 2.34.1
>
--
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation
