[Intel-gfx] [PATCH 4/4] drm/i915: Document FBC related w/as more thoroughly

[Souza, Jose]

On Wed, 2020-07-08 at 16:12 +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Pimp the comments for the FBC related workarounds.
> 

Reviewed-by: José Roberto de Souza <jose.souza at intel.com>

> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_pm.c | 55 ++++++++++++++++++++++++++-------
>  1 file changed, 44 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 7b98d0eb8597..da1d3ac09ae4 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -94,7 +94,10 @@ static void gen9_init_clock_gating(struct drm_i915_private *dev_priv)
>  	I915_WRITE(GEN8_CHICKEN_DCPR_1,
>  		   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
>  
> -	/* WaFbcWakeMemOn:skl,bxt,kbl,glk,cfl */
> +	/*
> +	 * WaFbcWakeMemOn:skl,bxt,kbl,glk,cfl
> +	 * Display WA #0859: skl,bxt,kbl,glk,cfl
> +	 */
>  	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
>  		   DISP_FBC_MEMORY_WAKE);
>  
> @@ -135,11 +138,17 @@ static void bxt_init_clock_gating(struct drm_i915_private *dev_priv)
>  	 */
>  	I915_WRITE(RM_TIMEOUT, MMIO_TIMEOUT_US(950));
>  
> -	/* WaFbcTurnOffFbcWatermark:bxt */
> +	/*
> +	 * WaFbcTurnOffFbcWatermark:bxt
> +	 * Display WA #0562: bxt
> +	 */
>  	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
>  		   DISP_FBC_WM_DIS);
>  
> -	/* WaFbcHighMemBwCorruptionAvoidance:bxt */
> +	/*
> +	 * WaFbcHighMemBwCorruptionAvoidance:bxt
> +	 * Display WA #0883: bxt
> +	 */
>  	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
>  		   ILK_DPFC_DISABLE_DUMMY0);
>  }
> @@ -7165,7 +7174,10 @@ static void cnl_init_clock_gating(struct drm_i915_private *dev_priv)
>  	I915_WRITE(GEN8_CHICKEN_DCPR_1,
>  		   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
>  
> -	/* WaFbcWakeMemOn:cnl */
> +	/*
> +	 * WaFbcWakeMemOn:cnl
> +	 * Display WA #0859: cnl
> +	 */
>  	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
>  		   DISP_FBC_MEMORY_WAKE);
>  
> @@ -7191,11 +7203,17 @@ static void cfl_init_clock_gating(struct drm_i915_private *dev_priv)
>  	cnp_init_clock_gating(dev_priv);
>  	gen9_init_clock_gating(dev_priv);
>  
> -	/* WaFbcTurnOffFbcWatermark:cfl */
> +	/*
> +	 * WaFbcTurnOffFbcWatermark:cfl
> +	 * Display WA #0562: cfl
> +	 */
>  	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
>  		   DISP_FBC_WM_DIS);
>  
> -	/* WaFbcNukeOnHostModify:cfl */
> +	/*
> +	 * WaFbcNukeOnHostModify:cfl
> +	 * Display WA #0873: cfl
> +	 */
>  	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
>  		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
>  }
> @@ -7214,11 +7232,17 @@ static void kbl_init_clock_gating(struct drm_i915_private *dev_priv)
>  		I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
>  			   GEN6_GAMUNIT_CLOCK_GATE_DISABLE);
>  
> -	/* WaFbcTurnOffFbcWatermark:kbl */
> +	/*
> +	 * WaFbcTurnOffFbcWatermark:kbl
> +	 * Display WA #0562: kbl
> +	 */
>  	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
>  		   DISP_FBC_WM_DIS);
>  
> -	/* WaFbcNukeOnHostModify:kbl */
> +	/*
> +	 * WaFbcNukeOnHostModify:kbl
> +	 * Display WA #0873: kbl
> +	 */
>  	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
>  		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
>  }
> @@ -7231,15 +7255,24 @@ static void skl_init_clock_gating(struct drm_i915_private *dev_priv)
>  	I915_WRITE(FBC_LLC_READ_CTRL, I915_READ(FBC_LLC_READ_CTRL) |
>  		   FBC_LLC_FULLY_OPEN);
>  
> -	/* WaFbcTurnOffFbcWatermark:skl */
> +	/*
> +	 * WaFbcTurnOffFbcWatermark:skl
> +	 * Display WA #0562: skl
> +	 */
>  	I915_WRITE(DISP_ARB_CTL, I915_READ(DISP_ARB_CTL) |
>  		   DISP_FBC_WM_DIS);
>  
> -	/* WaFbcNukeOnHostModify:skl */
> +	/*
> +	 * WaFbcNukeOnHostModify:skl
> +	 * Display WA #0873: skl
> +	 */
>  	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
>  		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
>  
> -	/* WaFbcHighMemBwCorruptionAvoidance:skl */
> +	/*
> +	 * WaFbcHighMemBwCorruptionAvoidance:skl
> +	 * Display WA #0883: skl
> +	 */
>  	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
>  		   ILK_DPFC_DISABLE_DUMMY0);
>  }