Re: [Intel-gfx] [PATCH v6 2/6] drm/i915/psr: Modify/Fix Wa_16013835468 and prepare for Wa_14015648006

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

On Wed, Mar 29, 2023 at 12:45:28PM +0300, Jouni Högander wrote:
> Wa_16013835468 is a separate from Wa_14015648006 and needs to be
> applied for TGL onwards. Fix this by removing all the references to
> Wa_14015648006 and apply Wa_16013835468 according to Bspec.
> 
> Also move workaround into separate function as a preparation for
> Wa_14015648006 implementation.
> 
> Bspec: 55378
> 
> v2:
>  - keep applying the wa in intel_psr_enable_source
> 
> Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_psr.c | 35 ++++++++++++++++--------
>  1 file changed, 24 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> index 8dbf452d63c2..26ad4365960f 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -1134,6 +1134,28 @@ static u32 wa_16013835468_bit_get(struct intel_dp *intel_dp)
>  	}
>  }
>  
> +/*
> + * Wa_16013835468
> + */
> +static void wm_optimization_wa(struct intel_dp *intel_dp,
> +			       const struct intel_crtc_state *crtc_state)
> +{
> +	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> +	bool set_wa_bit = false;
> +
> +	/* Wa_16013835468 */
> +	if (DISPLAY_VER(dev_priv) >= 12)

Looks like this should actually be == 12

> +		set_wa_bit |= crtc_state->hw.adjusted_mode.crtc_vblank_start !=
> +			crtc_state->hw.adjusted_mode.crtc_vdisplay;
> +
> +	if (set_wa_bit)
> +		intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1, 0,

Can you drop that 0 to the next line so the two branches
at least looks a bit more alike?

Alternatively
intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1,
	     wa_16013835468_bit_get(intel_dp),
	     set_wa_bit ? wa_16013835468_bit_get(intel_dp) : 0);
or something along those lines.

> +			     wa_16013835468_bit_get(intel_dp));
> +	else
> +		intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1,
> +			     wa_16013835468_bit_get(intel_dp), 0);
> +}
> +
>  static void intel_psr_enable_source(struct intel_dp *intel_dp,
>  				    const struct intel_crtc_state *crtc_state)
>  {
> @@ -1175,15 +1197,8 @@ static void intel_psr_enable_source(struct intel_dp *intel_dp,
>  
>  	/*
>  	 * Wa_16013835468
> -	 * Wa_14015648006
>  	 */
> -	if (IS_MTL_DISPLAY_STEP(dev_priv, STEP_A0, STEP_B0) ||
> -	    IS_DISPLAY_VER(dev_priv, 12, 13)) {
> -		if (crtc_state->hw.adjusted_mode.crtc_vblank_start !=
> -		    crtc_state->hw.adjusted_mode.crtc_vdisplay)
> -			intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1, 0,
> -				     wa_16013835468_bit_get(intel_dp));
> -	}
> +	wm_optimization_wa(intel_dp, crtc_state);
>  
>  	if (intel_dp->psr.psr2_enabled) {
>  		if (DISPLAY_VER(dev_priv) == 9)
> @@ -1359,10 +1374,8 @@ static void intel_psr_disable_locked(struct intel_dp *intel_dp)
>  
>  	/*
>  	 * Wa_16013835468
> -	 * Wa_14015648006
>  	 */
> -	if (IS_MTL_DISPLAY_STEP(dev_priv, STEP_A0, STEP_B0) ||
> -	    IS_DISPLAY_VER(dev_priv, 12, 13))
> +	if (DISPLAY_VER(dev_priv) >= 12)
>  		intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1,
>  			     wa_16013835468_bit_get(intel_dp), 0);
>  
> -- 
> 2.34.1

-- 
Ville Syrjälä
Intel