Re: [Intel-gfx] [PATCH 3/4] drm/i915/dg2: Drop pre-production GT workarounds

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Tue, 15 Aug 2023 10:36:15 -0700, Matt Roper wrote:
>

Hi Matt,

> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index 04bc1f4a1115..eadbfd2fb9e5 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -3381,25 +3381,6 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
>	intel_engine_pm_get(stream->engine);
>	intel_uncore_forcewake_get(stream->uncore, FORCEWAKE_ALL);
>
> -	/*
> -	 * Wa_16011777198:dg2: GuC resets render as part of the Wa. This causes
> -	 * OA to lose the configuration state. Prevent this by overriding GUCRC
> -	 * mode.
> -	 */
> -	if (intel_uc_uses_guc_rc(&gt->uc) &&
> -	    (IS_DG2_GRAPHICS_STEP(gt->i915, G10, STEP_A0, STEP_C0) ||
> -	     IS_DG2_GRAPHICS_STEP(gt->i915, G11, STEP_A0, STEP_B0))) {
> -		ret = intel_guc_slpc_override_gucrc_mode(&gt->uc.guc.slpc,
> -							 SLPC_GUCRC_MODE_GUCRC_NO_RC6);
> -		if (ret) {
> -			drm_dbg(&stream->perf->i915->drm,
> -				"Unable to override gucrc mode\n");
> -			goto err_gucrc;
> -		}
> -
> -		stream->override_gucrc = true;
> -	}
> -
>	ret = alloc_oa_buffer(stream);
>	if (ret)
>		goto err_oa_buf_alloc;
> @@ -3439,7 +3420,6 @@ static int i915_oa_stream_init(struct i915_perf_stream *stream,
>	if (stream->override_gucrc)
>		intel_guc_slpc_unset_gucrc_mode(&gt->uc.guc.slpc);
>
> -err_gucrc:
>	intel_uncore_forcewake_put(stream->uncore, FORCEWAKE_ALL);
>	intel_engine_pm_put(stream->engine);
>

If we are deleting this, let's basically remove all references to "gucrc"
in this file and includes. So:

* clean up the error path
* Remove stream->override_gucrc
* clean up i915_oa_stream_destroy

Maybe the functions intel_guc_slpc_unset_gucrc_mode and
intel_guc_slpc_override_gucrc_mode can also be removed.

Let's wait to hear from Umesh/Vinay (Cc'd) who implemented this stuff.

Thanks.
--
Ashutosh