[Intel-gfx] [PATCH v2 1/2] drm/i915/icl: Set GCP_COLOR_INDICATION only for 10/12 bit deep color

[Ville Syrjälä]

On Tue, Apr 02, 2019 at 05:14:39AM -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.

Why not? Table 6-1 in HDMI 1.4a spec clearly lists 8bpc as a
valid setting for GCP.

> 
> 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>
> ---
>  drivers/gpu/drm/i915/intel_hdmi.c | 31 +++++++++++++++----------------
>  1 file changed, 15 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> index 5ccb305a6e1c..4760462f84ca 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -963,7 +963,9 @@ static void intel_hdmi_compute_gcp_infoframe(struct intel_encoder *encoder,
>  		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))
> +
> +	if (hdmi_sink_is_deep_color(conn_state) &&
> +	    (crtc_state->pipe_bpp > 24))
>  		crtc_state->infoframes.gcp |= GCP_COLOR_INDICATION;
>  
>  	/* Enable default_phase whenever the display mode is suitably aligned */
> @@ -2260,6 +2262,7 @@ int intel_hdmi_compute_config(struct intel_encoder *encoder,
>  	int clock_8bpc = pipe_config->base.adjusted_mode.crtc_clock;
>  	int clock_10bpc = clock_8bpc * 5 / 4;
>  	int clock_12bpc = clock_8bpc * 3 / 2;
> +	int dc_clock = clock_12bpc;
>  	int desired_bpp;
>  	bool force_dvi = intel_conn_state->force_audio == HDMI_AUDIO_OFF_DVI;
>  
> @@ -2314,22 +2317,18 @@ int intel_hdmi_compute_config(struct intel_encoder *encoder,
>  	 * Note that g4x/vlv don't support 12bpc hdmi outputs. We also need
>  	 * to check that the higher clock still fits within limits.
>  	 */
> -	if (hdmi_deep_color_possible(pipe_config, 12) &&
> -	    hdmi_port_clock_valid(intel_hdmi, clock_12bpc,
> +	if (pipe_config->pipe_bpp == 30)
> +		dc_clock = clock_10bpc;
> +
> +	if (hdmi_deep_color_possible(pipe_config, pipe_config->pipe_bpp / 3) &&
> +	    hdmi_port_clock_valid(intel_hdmi, dc_clock,
>  				  true, force_dvi) == MODE_OK) {
> -		DRM_DEBUG_KMS("picking bpc to 12 for HDMI output\n");
> -		desired_bpp = 12*3;
> -
> -		/* Need to adjust the port link by 1.5x for 12bpc. */
> -		pipe_config->port_clock = clock_12bpc;
> -	} else if (hdmi_deep_color_possible(pipe_config, 10) &&
> -		   hdmi_port_clock_valid(intel_hdmi, clock_10bpc,
> -					 true, force_dvi) == MODE_OK) {
> -		DRM_DEBUG_KMS("picking bpc to 10 for HDMI output\n");
> -		desired_bpp = 10 * 3;
> -
> -		/* Need to adjust the port link by 1.25x for 10bpc. */
> -		pipe_config->port_clock = clock_10bpc;
> +		DRM_DEBUG_KMS("picking bpc to %d for HDMI output\n",
> +				 pipe_config->pipe_bpp / 3);
> +		desired_bpp = pipe_config->pipe_bpp;
> +
> +		/* Need to adjust the port link dc modes. */
> +		pipe_config->port_clock = dc_clock;

This part has nothing to do with the commit message.


>  	} else {
>  		DRM_DEBUG_KMS("picking bpc to 8 for HDMI output\n");
>  		desired_bpp = 8*3;
> -- 
> 2.17.1

-- 
Ville Syrjälä
Intel