[Intel-gfx] [PATCH 04/10] drm/i915: Extract chv_color_check()

[Matt Roper]

On Mon, Mar 18, 2019 at 06:13:11PM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Since CHV has the CGM unit we require a custom implementation
> of .color_check().
> 
> This fixes the computation of gamma_enable as previously we
> left it enabled even when were using the CGM gamma instead.
> Now we turn off the legacy LUT unless it's actually required.

The CGM stuff is a bit non-obvious to anyone who hasn't focused on the
CHV platform specifically, so it might be worth adding this
justification in a code comment.

In fact, a general overview comment somewhere (maybe on the CHV_COLORS
definition?) about the difference between legacy gamma and CGM might be
helpful.  It looks like our public PRM's for CHV don't really cover
anything display-wise.

Anyway, the code change looks correct, so

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>


Matt

> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_color.c | 28 ++++++++++++++++++++++++----
>  1 file changed, 24 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c
> index 3d19b1a7ee95..cb88651f1da4 100644
> --- a/drivers/gpu/drm/i915/intel_color.c
> +++ b/drivers/gpu/drm/i915/intel_color.c
> @@ -848,6 +848,29 @@ static u32 chv_cgm_mode(const struct intel_crtc_state *crtc_state)
>  	return cgm_mode;
>  }
>  
> +static int chv_color_check(struct intel_crtc_state *crtc_state)
> +{
> +	int ret;
> +
> +	ret = check_luts(crtc_state);
> +	if (ret)
> +		return ret;
> +
> +	crtc_state->gamma_enable =
> +		crtc_state_is_legacy_gamma(crtc_state) &&
> +		!crtc_state->c8_planes;
> +
> +	crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
> +
> +	crtc_state->cgm_mode = chv_cgm_mode(crtc_state);
> +
> +	ret = intel_color_add_affected_planes(crtc_state);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
>  static int _intel_color_check(struct intel_crtc_state *crtc_state)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
> @@ -877,9 +900,6 @@ static int _intel_color_check(struct intel_crtc_state *crtc_state)
>  
>  	crtc_state->csc_mode = 0;
>  
> -	if (IS_CHERRYVIEW(dev_priv))
> -		crtc_state->cgm_mode = chv_cgm_mode(crtc_state);
> -
>  	if (!crtc_state->gamma_enable ||
>  	    crtc_state_is_legacy_gamma(crtc_state))
>  		crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
> @@ -917,7 +937,7 @@ void intel_color_init(struct intel_crtc *crtc)
>  
>  	if (HAS_GMCH(dev_priv)) {
>  		if (IS_CHERRYVIEW(dev_priv)) {
> -			dev_priv->display.color_check = _intel_color_check;
> +			dev_priv->display.color_check = chv_color_check;
>  			dev_priv->display.color_commit = i9xx_color_commit;
>  			dev_priv->display.load_luts = cherryview_load_luts;
>  		} else {
> -- 
> 2.19.2
> 

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795