Re: [PATCH 10/20] drm/i915: add config function for YCBCR420 outputs

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Jul 13, 2017 at 10:56:06AM +0530, Sharma, Shashank wrote:
> Regards
> 
> Shashank
> 
> 
> On 7/12/2017 10:47 PM, Ville Syrjälä wrote:
> > On Mon, Jul 10, 2017 at 04:48:38PM +0530, Shashank Sharma wrote:
> >> This patch checks encoder level support for YCBCR420 outputs.
> >> The logic goes as simple as this:
> >> If the input mode is YCBCR420-only mode: prepare HDMI for
> >> YCBCR420 output, else continue with RGB output mode.
> >>
> >> It checks if the mode is YCBCR420 and source can support this
> >> output then it marks the ycbcr_420 output indicator into crtc
> >> state, for further staging in driver.
> >>
> >> V2: Split the patch into two, kept helper functions in DRM layer.
> >> V3: Changed the compute_config function based on new DRM API.
> >> V4: Rebase
> >> V5: Rebase
> >> V6: Check and handle YCBCR420-only modes, discard the property
> >>      based approach (Ville)
> >>
> >> Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
> >> ---
> >>   drivers/gpu/drm/i915/intel_display.c |  1 +
> >>   drivers/gpu/drm/i915/intel_drv.h     |  3 +++
> >>   drivers/gpu/drm/i915/intel_hdmi.c    | 42 +++++++++++++++++++++++++++++++++---
> >>   3 files changed, 43 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> >> index 4e03ca6..01900e1 100644
> >> --- a/drivers/gpu/drm/i915/intel_display.c
> >> +++ b/drivers/gpu/drm/i915/intel_display.c
> >> @@ -11930,6 +11930,7 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
> >>   	PIPE_CONF_CHECK_I(hdmi_scrambling);
> >>   	PIPE_CONF_CHECK_I(hdmi_high_tmds_clock_ratio);
> >>   	PIPE_CONF_CHECK_I(has_infoframe);
> >> +	PIPE_CONF_CHECK_I(ycbcr420);
> >>   
> >>   	PIPE_CONF_CHECK_I(has_audio);
> >>   
> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> >> index d17a324..592243b 100644
> >> --- a/drivers/gpu/drm/i915/intel_drv.h
> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
> >> @@ -780,6 +780,9 @@ struct intel_crtc_state {
> >>   
> >>   	/* HDMI High TMDS char rate ratio */
> >>   	bool hdmi_high_tmds_clock_ratio;
> >> +
> >> +	/* HDMI output type */
> >> +	bool ycbcr420;
> >>   };
> >>   
> >>   struct intel_crtc {
> >> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> >> index cc0d100..276d916 100644
> >> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> >> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> >> @@ -1305,7 +1305,8 @@ intel_hdmi_mode_valid(struct drm_connector *connector,
> >>   	return status;
> >>   }
> >>   
> >> -static bool hdmi_12bpc_possible(struct intel_crtc_state *crtc_state)
> >> +static bool hdmi_12bpc_possible(struct intel_crtc_state *crtc_state,
> >> +				bool output_ycbcr420)
> > You alreayd have the crtc state, so no need to pass that stuff
> > separately.
> Ah, this was dumb, thanks !
> >>   {
> >>   	struct drm_i915_private *dev_priv =
> >>   		to_i915(crtc_state->base.crtc->dev);
> >> @@ -1330,6 +1331,13 @@ static bool hdmi_12bpc_possible(struct intel_crtc_state *crtc_state)
> >>   		if (connector_state->crtc != crtc_state->base.crtc)
> >>   			continue;
> >>   
> >> +		if (output_ycbcr420) {
> >> +			const struct drm_hdmi_info *hdmi = &info->hdmi;
> >> +
> >> +			if (!(hdmi->y420_dc_modes & DRM_EDID_YCBCR420_DC_36))
> >> +				return false;
> >> +		}
> >> +
> > else?
> Oops, needs an else { break;}

I was thinking 'else if ...'

> 
> - Shashank
> >
> >>   		if ((info->edid_hdmi_dc_modes & DRM_EDID_HDMI_DC_36) == 0)
> >>   			return false;
> >>   	}
> >> @@ -1342,6 +1350,25 @@ static bool hdmi_12bpc_possible(struct intel_crtc_state *crtc_state)
> >>   	return true;
> >>   }
> >>   
> >> +static bool
> >> +intel_hdmi_ycbcr420_config(struct drm_connector *connector,
> >> +			       struct intel_crtc_state *config,
> >> +			       int *clock_12bpc, int *clock_8bpc)
> >> +{
> >> +
> >> +	if (!connector->ycbcr_420_allowed) {
> >> +		DRM_ERROR("Platform doesn't support YCBCR420 output\n");
> >> +		return false;
> >> +	}
> >> +
> >> +	/* YCBCR420 TMDS rate requirement is half the pixel clock */
> >> +	config->port_clock /= 2;
> >> +	*clock_12bpc /= 2;
> >> +	*clock_8bpc /= 2;
> >> +	config->ycbcr420 = true;
> >> +	return true;
> >> +}
> >> +
> >>   bool intel_hdmi_compute_config(struct intel_encoder *encoder,
> >>   			       struct intel_crtc_state *pipe_config,
> >>   			       struct drm_connector_state *conn_state)
> >> @@ -1349,7 +1376,8 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
> >>   	struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(&encoder->base);
> >>   	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> >>   	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> >> -	struct drm_scdc *scdc = &conn_state->connector->display_info.hdmi.scdc;
> >> +	struct drm_connector *connector = conn_state->connector;
> >> +	struct drm_scdc *scdc = &connector->display_info.hdmi.scdc;
> >>   	struct intel_digital_connector_state *intel_conn_state =
> >>   		to_intel_digital_connector_state(conn_state);
> >>   	int clock_8bpc = pipe_config->base.adjusted_mode.crtc_clock;
> >> @@ -1379,6 +1407,14 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
> >>   		clock_12bpc *= 2;
> >>   	}
> >>   
> >> +	if (drm_mode_is_420_only(&connector->display_info, adjusted_mode)) {
> >> +		if (!intel_hdmi_ycbcr420_config(connector, pipe_config,
> >> +						&clock_12bpc, &clock_8bpc)) {
> >> +			DRM_ERROR("Can't support YCBCR420 output\n");
> >> +			return false;
> >> +		}
> >> +	}
> >> +
> >>   	if (HAS_PCH_SPLIT(dev_priv) && !HAS_DDI(dev_priv))
> >>   		pipe_config->has_pch_encoder = true;
> >>   
> >> @@ -1398,7 +1434,7 @@ bool intel_hdmi_compute_config(struct intel_encoder *encoder,
> >>   	 */
> >>   	if (pipe_config->pipe_bpp > 8*3 && pipe_config->has_hdmi_sink && !force_dvi &&
> >>   	    hdmi_port_clock_valid(intel_hdmi, clock_12bpc, true, force_dvi) == MODE_OK &&
> >> -	    hdmi_12bpc_possible(pipe_config)) {
> >> +	    hdmi_12bpc_possible(pipe_config, pipe_config->ycbcr420)) {
> >>   		DRM_DEBUG_KMS("picking bpc to 12 for HDMI output\n");
> >>   		desired_bpp = 12*3;
> >>   
> >> -- 
> >> 2.7.4
> >>
> >> _______________________________________________
> >> dri-devel mailing list
> >> dri-devel@lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Ville Syrjälä
Intel OTC
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