[Intel-gfx] [PATCH 2/4] drm/i915: Nuke the magic FBC_CONTROL save/restore

[Jani Nikula]

On Tue, 08 Sep 2020, Ville Syrjala <ville.syrjala at linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> The FBC_CONTROL save restore is there just to preserve the
> compression interval setting. Since commit a68ce21ba0c4
> ("drm/i915/fbc: Store the fbc1 compression interval in the params")
> we've been explicitly setting the interval to a specific
> value, so the sace/restore is now entirely pointless.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Seems legit,

Reviewed-by: Jani Nikula <jani.nikula at intel.com>

> ---
>  drivers/gpu/drm/i915/i915_drv.h     | 1 -
>  drivers/gpu/drm/i915/i915_suspend.c | 8 --------
>  2 files changed, 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 2e4438e8e3eb..3917bb1a6157 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -537,7 +537,6 @@ struct intel_gmbus {
>  
>  struct i915_suspend_saved_registers {
>  	u32 saveDSPARB;
> -	u32 saveFBC_CONTROL;
>  	u32 saveCACHE_MODE_0;
>  	u32 saveMI_ARB_STATE;
>  	u32 saveSWF0[16];
> diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
> index ed2be3489f8e..592c230e6914 100644
> --- a/drivers/gpu/drm/i915/i915_suspend.c
> +++ b/drivers/gpu/drm/i915/i915_suspend.c
> @@ -37,10 +37,6 @@ static void i915_save_display(struct drm_i915_private *dev_priv)
>  	/* Display arbitration control */
>  	if (INTEL_GEN(dev_priv) <= 4)
>  		dev_priv->regfile.saveDSPARB = I915_READ(DSPARB);
> -
> -	/* save FBC interval */
> -	if (HAS_FBC(dev_priv) && INTEL_GEN(dev_priv) <= 4 && !IS_G4X(dev_priv))
> -		dev_priv->regfile.saveFBC_CONTROL = I915_READ(FBC_CONTROL);
>  }
>  
>  static void i915_restore_display(struct drm_i915_private *dev_priv)
> @@ -52,10 +48,6 @@ static void i915_restore_display(struct drm_i915_private *dev_priv)
>  	/* only restore FBC info on the platform that supports FBC*/
>  	intel_fbc_global_disable(dev_priv);
>  
> -	/* restore FBC interval */
> -	if (HAS_FBC(dev_priv) && INTEL_GEN(dev_priv) <= 4 && !IS_G4X(dev_priv))
> -		I915_WRITE(FBC_CONTROL, dev_priv->regfile.saveFBC_CONTROL);
> -
>  	intel_vga_redisable(dev_priv);
>  }

-- 
Jani Nikula, Intel Open Source Graphics Center