[Intel-gfx] [PATCH] drm/i915: Move the min_pixclk[] handling to the end of readout

[Maarten Lankhorst]

Op 20-12-16 om 16:39 schreef ville.syrjala at linux.intel.com:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Trying to determine the pixel rate of the pipe can't be done until we
> know the clock, which means it can't be done until the encoder
> .get_config() hooks have been called. So let's move the min_pixclk[]
> stuff to the end of intel_modeset_readout_hw_state() when we actually
> have gathered all the required infromation.
>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Mika Kahola <mika.kahola at intel.com>
> Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira at intel.com>
> Fixes: 565602d7501a ("drm/i915: Do not acquire crtc state to check clock during modeset, v4.")
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 32 ++++++++++++++++----------------
>  1 file changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index ef5dde5ab1cf..d8effd4da034 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -17033,7 +17033,6 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  
>  	for_each_intel_crtc(dev, crtc) {
>  		struct intel_crtc_state *crtc_state = crtc->config;
> -		int pixclk = 0;
>  
>  		__drm_atomic_helper_crtc_destroy_state(&crtc_state->base);
>  		memset(crtc_state, 0, sizeof(*crtc_state));
> @@ -17045,23 +17044,9 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  		crtc->base.enabled = crtc_state->base.enable;
>  		crtc->active = crtc_state->base.active;
>  
> -		if (crtc_state->base.active) {
> +		if (crtc_state->base.active)
>  			dev_priv->active_crtcs |= 1 << crtc->pipe;
>  
> -			if (INTEL_GEN(dev_priv) >= 9 || IS_BROADWELL(dev_priv))
> -				pixclk = ilk_pipe_pixel_rate(crtc_state);
> -			else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> -				pixclk = crtc_state->base.adjusted_mode.crtc_clock;
> -			else
> -				WARN_ON(dev_priv->display.modeset_calc_cdclk);
> -
> -			/* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
> -			if (IS_BROADWELL(dev_priv) && crtc_state->ips_enabled)
> -				pixclk = DIV_ROUND_UP(pixclk * 100, 95);
> -		}
> -
> -		dev_priv->min_pixclk[crtc->pipe] = pixclk;
> -
>  		readout_plane_state(crtc);
>  
>  		DRM_DEBUG_KMS("[CRTC:%d:%s] hw state readout: %s\n",
> @@ -17134,6 +17119,8 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  	}
>  
>  	for_each_intel_crtc(dev, crtc) {
> +		int pixclk = 0;
> +
>  		crtc->base.hwmode = crtc->config->base.adjusted_mode;
>  
>  		memset(&crtc->base.mode, 0, sizeof(crtc->base.mode));
> @@ -17161,10 +17148,23 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
>  			 */
>  			crtc->base.state->mode.private_flags = I915_MODE_FLAG_INHERITED;
>  
> +			if (INTEL_GEN(dev_priv) >= 9 || IS_BROADWELL(dev_priv))
> +				pixclk = ilk_pipe_pixel_rate(crtc->config);
> +			else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> +				pixclk = crtc->config->base.adjusted_mode.crtc_clock;
> +			else
> +				WARN_ON(dev_priv->display.modeset_calc_cdclk);
> +
> +			/* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
> +			if (IS_BROADWELL(dev_priv) && crtc->config->ips_enabled)
> +				pixclk = DIV_ROUND_UP(pixclk * 100, 95);
> +
>  			drm_calc_timestamping_constants(&crtc->base, &crtc->base.hwmode);
>  			update_scanline_offset(crtc);
>  		}
>  
> +		dev_priv->min_pixclk[crtc->pipe] = pixclk;
> +
>  		intel_pipe_config_sanity_check(dev_priv, crtc->config);
>  	}
>  }

Looks good. Could you do intel_crtc_state = to_intel_crtc_state(crtc->base.state) at the start
and fix all ->state and ->config dereferences in this loop too?
This is a cleanup I'm trying to apply to the whole driver. Atomic state should be
passed in where possible, and crtc->config/state dereferences should be avoided as much as we can.
Eventually I want to get rid of crtc->config altogether. :)

Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>