[Intel-gfx] [PATCH v6 2/2] drm/i915: Skip modeset for cdclk changes if possible

Ville Syrjälä ville.syrjala at linux.intel.com
Mon Mar 18 18:37:33 UTC 2019


On Mon, Mar 18, 2019 at 04:34:35PM +0200, Imre Deak wrote:
> @@ -2137,6 +2194,44 @@ void intel_set_cdclk(struct drm_i915_private *dev_priv,
>  	}
>  }
>  
> +/**
> + * intel_set_cdclk_pre_plane_update - Push the CDCLK state to the hardware
> + * @dev_priv: i915 device
> + * @cdclk_state: new CDCLK state
> + * @pipe: pipe with which to synchronize the update
> + *
> + * Program the hardware before updating the HW plane state based on the passed
> + * in CDCLK state, if necessary.
> + */
> +void
> +intel_set_cdclk_pre_plane_update(struct drm_i915_private *dev_priv,
> +				 const struct intel_cdclk_state *cdclk_state,
> +				 enum pipe pipe)
> +{
> +	if (pipe == INVALID_PIPE ||
> +	    dev_priv->cdclk.actual.cdclk >= cdclk_state->cdclk)

cdclk_state == &dev_priv->cdclk.actual
so these look a bit buggered.

Would be somewhat nice to use the private obj stuff for this but
the locking now enforced by that make it difficult. Perhaps a
swap(dev_priv->cdlk, state->cdclk) would be possible? A quick scan
through the code didn't reveal any uses of state->cdclk outside the
compute code paths, so looks safeish. Another option is just
comparing against dev_priv->cdclk.hw since we still have that.

> +		intel_set_cdclk(dev_priv, cdclk_state, pipe);
> +}
> +
> +/**
> + * intel_set_cdclk_post_plane_update - Push the CDCLK state to the hardware
> + * @dev_priv: i915 device
> + * @cdclk_state: new CDCLK state
> + * @pipe: pipe with which to synchronize the update
> + *
> + * Program the hardware after updating the HW plane state based on the passed
> + * in CDCLK state, if necessary.
> + */
> +void
> +intel_set_cdclk_post_plane_update(struct drm_i915_private *dev_priv,
> +				  const struct intel_cdclk_state *cdclk_state,
> +				  enum pipe pipe)
> +{
> +	if (pipe != INVALID_PIPE &&
> +	    dev_priv->cdclk.actual.cdclk < cdclk_state->cdclk)
> +		intel_set_cdclk(dev_priv, cdclk_state, pipe);
> +}
> +
>  static int intel_pixel_rate_to_cdclk(struct drm_i915_private *dev_priv,
>  				     int pixel_rate)
>  {
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index b4199cd53349..0f9884ec7e8e 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12982,6 +12982,7 @@ static int intel_modeset_checks(struct drm_atomic_state *state)
>  	intel_state->active_crtcs = dev_priv->active_crtcs;
>  	intel_state->cdclk.logical = dev_priv->cdclk.logical;
>  	intel_state->cdclk.actual = dev_priv->cdclk.actual;
> +	intel_state->cdclk.pipe = INVALID_PIPE;
>  
>  	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
>  		if (new_crtc_state->active)
> @@ -13001,6 +13002,8 @@ static int intel_modeset_checks(struct drm_atomic_state *state)
>  	 * adjusted_mode bits in the crtc directly.
>  	 */
>  	if (dev_priv->display.modeset_calc_cdclk) {
> +		enum pipe pipe;
> +
>  		ret = dev_priv->display.modeset_calc_cdclk(state);
>  		if (ret < 0)
>  			return ret;
> @@ -13017,12 +13020,36 @@ static int intel_modeset_checks(struct drm_atomic_state *state)
>  				return ret;
>  		}
>  
> +		if (is_power_of_2(intel_state->active_crtcs)) {
> +			struct drm_crtc *crtc;
> +			struct drm_crtc_state *crtc_state;
> +
> +			pipe = ilog2(intel_state->active_crtcs);
> +			crtc = &intel_get_crtc_for_pipe(dev_priv, pipe)->base;
> +			crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> +			if (crtc_state && needs_modeset(crtc_state))
> +				pipe = INVALID_PIPE;
> +		} else {
> +			pipe = INVALID_PIPE;
> +		}
> +
>  		/* All pipes must be switched off while we change the cdclk. */
> -		if (intel_cdclk_needs_modeset(&dev_priv->cdclk.actual,
> -					      &intel_state->cdclk.actual)) {
> +		if (pipe != INVALID_PIPE &&
> +		    intel_cdclk_needs_cd2x_update(dev_priv,
> +						  &dev_priv->cdclk.actual,
> +						  &intel_state->cdclk.actual)) {
> +			ret = intel_lock_all_pipes(state);
> +			if (ret < 0)
> +				return ret;
> +
> +			intel_state->cdclk.pipe = pipe;
> +		} else if (intel_cdclk_needs_modeset(&dev_priv->cdclk.actual,
> +						     &intel_state->cdclk.actual)) {
>  			ret = intel_modeset_all_pipes(state);
>  			if (ret < 0)
>  				return ret;
> +
> +			intel_state->cdclk.pipe = INVALID_PIPE;
>  		}
>  
>  		DRM_DEBUG_KMS("New cdclk calculated to be logical %u kHz, actual %u kHz\n",
> @@ -13433,7 +13460,9 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
>  	if (intel_state->modeset) {
>  		drm_atomic_helper_update_legacy_modeset_state(state->dev, state);
>  
> -		intel_set_cdclk(dev_priv, &dev_priv->cdclk.actual);
> +		intel_set_cdclk_pre_plane_update(dev_priv,
> +						 &dev_priv->cdclk.actual,
> +						 intel_state->cdclk.pipe);
>  
>  		/*
>  		 * SKL workaround: bspec recommends we disable the SAGV when we
> @@ -13462,6 +13491,10 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
>  	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
>  	dev_priv->display.update_crtcs(state);
>  
> +	intel_set_cdclk_post_plane_update(dev_priv,
> +					  &dev_priv->cdclk.actual,
> +					  intel_state->cdclk.pipe);
> +
>  	/* FIXME: We should call drm_atomic_helper_commit_hw_done() here
>  	 * already, but still need the state for the delayed optimization. To
>  	 * fix this:
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 0b84e557c267..e5a1e245ee65 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -559,6 +559,8 @@ struct intel_atomic_state {
>  
>  		int force_min_cdclk;
>  		bool force_min_cdclk_changed;
> +		/* pipe to which cd2x update is synchronized */
> +		enum pipe pipe;
>  	} cdclk;
>  
>  	bool dpll_set, modeset;
> @@ -1694,12 +1696,21 @@ void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv);
>  void intel_update_max_cdclk(struct drm_i915_private *dev_priv);
>  void intel_update_cdclk(struct drm_i915_private *dev_priv);
>  void intel_update_rawclk(struct drm_i915_private *dev_priv);
> +bool intel_cdclk_needs_cd2x_update(struct drm_i915_private *dev_priv,
> +				   const struct intel_cdclk_state *a,
> +				   const struct intel_cdclk_state *b);
>  bool intel_cdclk_needs_modeset(const struct intel_cdclk_state *a,
>  			       const struct intel_cdclk_state *b);
>  bool intel_cdclk_changed(const struct intel_cdclk_state *a,
>  			 const struct intel_cdclk_state *b);
> -void intel_set_cdclk(struct drm_i915_private *dev_priv,
> -		     const struct intel_cdclk_state *cdclk_state);
> +void
> +intel_set_cdclk_pre_plane_update(struct drm_i915_private *dev_priv,
> +				 const struct intel_cdclk_state *cdclk_state,
> +				 enum pipe pipe);
> +void
> +intel_set_cdclk_post_plane_update(struct drm_i915_private *dev_priv,
> +				  const struct intel_cdclk_state *cdclk_state,
> +				  enum pipe pipe);
>  void intel_dump_cdclk_state(const struct intel_cdclk_state *cdclk_state,
>  			    const char *context);
>  
> -- 
> 2.13.2

-- 
Ville Syrjälä
Intel


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