[Intel-gfx] [PATCH v8] drm/i915/icl: Set GCP_COLOR_INDICATION only for 10/12 bit deep color

[Ville Syrjälä]

On Thu, Apr 25, 2019 at 06:19:50PM -0700, Aditya Swarup wrote:
> From: Clinton Taylor <Clinton.A.Taylor at intel.com>
> 
> v2: Fix commit msg to reflect why issue occurs(Jani)
> Set GCP_COLOR_INDICATION only when we set 10/12 bit deep color.
> 
> Changing settings from 10/12 bit deep color to 8 bit(& vice versa)
> doesn't work correctly using xrandr max bpc property. When we
> connect a monitor which supports deep color, the highest deep color
> setting is selected; which sets GCP_COLOR_INDICATION. When we change
> the setting to 8 bit color, we still set GCP_COLOR_INDICATION which
> doesn't allow the switch back to 8 bit color.
> 
> v3,4: Add comments & drop changes in intel_hdmi_compute_config(Ville)
> Since HSW+, GCP_COLOR_INDICATION is not required for 8bpc.
> 
> Drop the changes in intel_hdmi_compute_config as desired_bpp
> is needed to change values for pipe_bpp based on bw_constrained flag.
> 
> v5: Fix missing logical && in condition for setting GCP_COLOR_INDICATION.
> 
> v6: Fix comment formatting (Ville)
> 
> v7: Add reviewed by Ville
> 
> v8: Set GCP_COLOR_INDICATION based on spec:
> For Gen 7.5 or later platforms, indicate color depth only for deep
> color modes. Bspec: 8135,7751,50524
> 
> Pre DDI platforms, indicate color depth if deep color is supported
> by sink. Bspec: 7854
> 
> Exception: CHERRYVIEW behaves like Pre DDI platforms.
> Bspec: 15975
> 
> Check pipe_bpp is less than bpp * 3 in hdmi_deep_color_possible,
> to not set 12 bit deep color for every modeset. This fixes the issue
> where 12 bit color was selected even when user selected 10 bit.(Ville)
> 
> Co-Developed-by: Aditya Swarup <aditya.swarup at intel.com>
> Co-Developed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Clinton Taylor <Clinton.A.Taylor at intel.com>
> Signed-off-by: Aditya Swarup <aditya.swarup at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Cc: Manasi Navare <manasi.d.navare at intel.com>
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_hdmi.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> index e1005d7b75fd..620bc89e2120 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -973,9 +973,18 @@ static void intel_hdmi_compute_gcp_infoframe(struct intel_encoder *encoder,
>  	crtc_state->infoframes.enable |=
>  		intel_hdmi_infoframe_enable(HDMI_PACKET_TYPE_GENERAL_CONTROL);
>  
> -	/* Indicate color depth whenever the sink supports deep color */
> -	if (hdmi_sink_is_deep_color(conn_state))
> -		crtc_state->infoframes.gcp |= GCP_COLOR_INDICATION;
> +	/* Indicate color depth whenever the sink supports deep color:
> +	 * For Gen 7.5 or later platforms, indicate color depth only for deep
> +	 * color modes.
> +	 * Pre DDI platforms, indicate color depth if deep color is supported
> +	 * by sink.
> +	 * Exception: CHERRYVIEW behaves like Pre DDI platforms.
> +	 */
> +	if (hdmi_sink_is_deep_color(conn_state)) {
> +		if(!HAS_DDI(dev_priv) || IS_CHERRYVIEW(dev_priv) ||
> +		   crtc_state->pipe_bpp > 24)

I prefer the earlier version. Less special casing.

> +			crtc_state->infoframes.gcp |= GCP_COLOR_INDICATION;
> +	}
>  
>  	/* Enable default_phase whenever the display mode is suitably aligned */
>  	if (gcp_default_phase_possible(crtc_state->pipe_bpp,
> @@ -2172,7 +2181,7 @@ static bool hdmi_deep_color_possible(const struct intel_crtc_state *crtc_state,
>  	if (bpc == 10 && INTEL_GEN(dev_priv) < 11)
>  		return false;
>  
> -	if (crtc_state->pipe_bpp <= 8*3)
> +	if (crtc_state->pipe_bpp < bpc*3)

This should be a separate patch.

>  		return false;
>  
>  	if (!crtc_state->has_hdmi_sink)
> -- 
> 2.17.1

-- 
Ville Syrjälä
Intel