[Intel-gfx] [PATCH 21/25] drm/i915/gen9: Add WaFbcTurnOffFbcWatermark

[Ville Syrjälä]

On Mon, May 30, 2016 at 06:10:20PM +0300, Mika Kuoppala wrote:
> According to bspec this prevents screen corruption when fbc is
> used.
> 
> v2: This workaround has a name, use it (Ville)
> v3: remove bogus gen check on ilk/vlv wm path (Ville)
> 
> References: HSD#2135555, HSD#2137270, BSID#562
> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/intel_pm.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 9ae1b0646678..6b972ae53bec 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -68,6 +68,10 @@ static void gen9_init_clock_gating(struct drm_device *dev)
>  	/* WaEnableChickenDCPR:skl,bxt,kbl */
>  	I915_WRITE(GEN8_CHICKEN_DCPR_1,
>  		   I915_READ(GEN8_CHICKEN_DCPR_1) | MASK_WAKEMEM);
> +
> +	/* WaFbcTurnOffFbcWatermark:skl,bxt,kbl */
> +	I915_WRITE(DISP_ARB_CTL,
> +		   I915_READ(DISP_ARB_CTL) | DISP_FBC_WM_DIS);
>  }
>  
>  static void bxt_init_clock_gating(struct drm_device *dev)
> -- 
> 2.5.0

-- 
Ville Syrjälä
Intel OTC