Re: [PATCH v3] drm/i915/chv: Implement WaDisableShadowRegForCpd

Ville Syrjälä
2015-04-15T18:39:51Z

On Wed, Apr 15, 2015 at 07:41:39PM +0530, deepak.s@linux.intel.com wrote:
> From: Deepak S <deepak.s@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@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@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