[Intel-gfx] [PATCH v3] drm/i915/chv: Implement WaDisableShadowRegForCpd

[Ville Syrjälä]

On Wed, Apr 15, 2015 at 07:41:39PM +0530, deepak.s at linux.intel.com wrote:
> From: Deepak S <deepak.s at linux.intel.com>
> 
> This WA is avoid problem between shadow vs wake FIFO unload
> problem during CPD/RC6 transactions on CHV.
> 
> v2: Define individual bits GTFIFOCTL (Ville)
> 
> v3: move WA to uncore_early_sanitize (ville)
> 
> Signed-off-by: Deepak S <deepak.s at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h     | 2 ++
>  drivers/gpu/drm/i915/intel_uncore.c | 8 ++++++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 9c97842..a642a58 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -6206,6 +6206,8 @@ enum skl_disp_power_wells {
>  #define  GTFIFOCTL				0x120008
>  #define    GT_FIFO_FREE_ENTRIES_MASK		0x7f
>  #define    GT_FIFO_NUM_RESERVED_ENTRIES		20
> +#define	   GT_FIFO_CTL_BLOCK_ALL_POLICY_STALL	(1 << 12)
> +#define	   GT_FIFO_CTL_RC6_POLICY_STALL	(1 << 11)
>  
>  #define  HSW_IDICR				0x9008
>  #define    IDIHASHMSK(x)			(((x) & 0x3f) << 16)
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index d96d15f..26d6dda 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -360,6 +360,14 @@ static void __intel_uncore_early_sanitize(struct drm_device *dev,
>  		__raw_i915_write32(dev_priv, GTFIFODBG,
>  				   __raw_i915_read32(dev_priv, GTFIFODBG));
>  
> +	/* WaDisableShadowRegForCpd */

I couldn't find this w/a name anywhere official, but I guess it's fine.
Should be WaDisableShadowRegForCpd:chv though. Otherwise looks good, so

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

> +	if (IS_CHERRYVIEW(dev)) {
> +		__raw_i915_write32(dev_priv, GTFIFOCTL,
> +				__raw_i915_read32(dev_priv, GTFIFOCTL) |
> +						GT_FIFO_CTL_BLOCK_ALL_POLICY_STALL |
> +						GT_FIFO_CTL_RC6_POLICY_STALL);
> +	}
> +
>  	intel_uncore_forcewake_reset(dev, restore_forcewake);
>  }
>  
> -- 
> 1.9.1

-- 
Ville Syrjälä
Intel OTC