Re: [Intel-gfx] [PATCH v5 6/6] drm/i915/psr: Implement Display WA #1136

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Mar 22, 2023 at 12:34:12PM +0200, Jouni Högander wrote:
> Implement Display WA #1136 for SKL/BXT.


> 
> Bspec: 21664
> 
> Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_psr.c     | 17 +++++++++++++++++
>  drivers/gpu/drm/i915/display/skl_watermark.c |  5 -----
>  2 files changed, 17 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> index b53c71c06105..24c3f75bb9d8 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -1950,6 +1950,7 @@ void intel_psr_pre_plane_update(struct intel_atomic_state *state,
>  /*
>   * Wa_16013835468
>   * Wa_14015648006
> + * Display WA #1136: skl, bxt
>   */
>  static void wm_optimization_wa(struct intel_dp *intel_dp,
>  			   const struct intel_crtc_state *crtc_state)
> @@ -1957,6 +1958,17 @@ static void wm_optimization_wa(struct intel_dp *intel_dp,
>  	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
>  	bool set_wa_bit = false;
>  
> +	/*
> +	 * Display WA #1136: skl, bxt
> +	 * skl/bxt do not have chicken bit: disable PSR
> +	 */
> +	if (DISPLAY_VER(dev_priv) <= 9) {

If we limit the chicken bit to icl+ for now then this stuff
needs to be 'DISPLAY_VER < 11'.


> +		if (crtc_state->wm_level_disabled &&
> +		    intel_dp->psr.enabled)
> +			intel_psr_disable_locked(intel_dp);

This seems like it should be part of the pre_plane_update psr
disable.

> +		return;
> +	}
> +
>  	/* Wa_14015648006 */
>  	if (IS_MTL_DISPLAY_STEP(dev_priv, STEP_A0, STEP_B0) ||
>  	    IS_DISPLAY_VER(dev_priv, 11, 13))
> @@ -1999,12 +2011,17 @@ static void _intel_psr_post_plane_update(const struct intel_atomic_state *state,
>  		keep_disabled |= psr->sink_not_reliable;
>  		keep_disabled |= !crtc_state->active_planes;
>  
> +		/* Display WA #1136: skl, bxt */
> +		keep_disabled |= DISPLAY_VER(dev_priv) <= 9 &&
> +			crtc_state->wm_level_disabled;
> +
>  		if (!psr->enabled && !keep_disabled)
>  			intel_psr_enable_locked(intel_dp, crtc_state);
>  
>  		/*
>  		 * Wa_16013835468
>  		 * Wa_14015648006
> +		 * Display WA #1136: skl, bxt
>  		 */
>  		wm_optimization_wa(intel_dp, crtc_state);
>  
> diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
> index afb751c024ba..ced61da8b496 100644
> --- a/drivers/gpu/drm/i915/display/skl_watermark.c
> +++ b/drivers/gpu/drm/i915/display/skl_watermark.c
> @@ -2278,11 +2278,6 @@ static int skl_wm_check_vblank(struct intel_crtc_state *crtc_state)
>  	 */
>  	crtc_state->wm_level_disabled = level < i915->display.wm.num_levels - 1;
>  
> -	/*
> -	 * FIXME also related to skl+ w/a 1136 (also unimplemented as of
> -	 * now) perhaps?
> -	 */
> -
>  	for (level++; level < i915->display.wm.num_levels; level++) {
>  		enum plane_id plane_id;
>  
> -- 
> 2.34.1

-- 
Ville Syrjälä
Intel