Re: [Intel-gfx] [PATCH 3/5] drm/i915/dp: Fix DFP RGB->YCBCR conversion

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 8/24/2022 2:07 PM, Jani Nikula wrote:
> On Wed, 24 Aug 2022, "Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com> wrote:
>> On 8/23/2022 4:33 PM, Jani Nikula wrote:
>>> On Mon, 22 Aug 2022, Ankit Nautiyal <ankit.k.nautiyal@intel.com> wrote:
>>>> The decision to use DFP output format conversion capabilities should be
>>>> during compute_config phase.
>>>>
>>>> This patch:
>>>> -uses the members of intel_dp->dfp to only store the
>>>> format conversion capabilities of the DP device.
>>>> -adds new members to crtc_state to help configure the DFP
>>>> output related conversions.
>>>> -pulls the decision making to use DFP conversion capabilities
>>>> for every mode during compute config.
>>> The fact that you have a list here probably indicates it's doing too
>>> much at once.
>>>
>>> BR,
>>> Jani.
>> Alright, perhaps adding new members as a separate patch and using them
>> in another patch will be better.
>>
>> Will split this into smaller patches.
> You are also changing function parameters, rearranging stuff to new
> functions, whitespace changes, functional logic changes, all together.
>
> The point is, if an existing use case regressed and a user bisect
> pointed at this commit, would you be able to say what went wrong?
>
> BR,
> Jani.

Got it. Indeed it will be difficult to root cause the issue in a patch 
like this.

I will try to get this in smaller incremental changes.

Regards,

Ankit

>
>> Thanks & Regards,
>>
>> Ankit
>>
>>>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
>>>> ---
>>>>    .../drm/i915/display/intel_display_types.h    |  7 ++
>>>>    drivers/gpu/drm/i915/display/intel_dp.c       | 88 +++++++++++--------
>>>>    2 files changed, 59 insertions(+), 36 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
>>>> index 0da9b208d56e..065ed19a5dd3 100644
>>>> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
>>>> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
>>>> @@ -1311,6 +1311,12 @@ struct intel_crtc_state {
>>>>    
>>>>    	/* for loading single buffered registers during vblank */
>>>>    	struct drm_vblank_work vblank_work;
>>>> +
>>>> +	/* DP DFP color configuration */
>>>> +	struct {
>>>> +		bool rgb_to_ycbcr;
>>>> +		bool ycbcr_444_to_420;
>>>> +	} dp_dfp_config;
>>>>    };
>>>>    
>>>>    enum intel_pipe_crc_source {
>>>> @@ -1704,6 +1710,7 @@ struct intel_dp {
>>>>    		int pcon_max_frl_bw;
>>>>    		u8 max_bpc;
>>>>    		bool ycbcr_444_to_420;
>>>> +		bool ycbcr420_passthrough;
>>>>    		bool rgb_to_ycbcr;
>>>>    	} dfp;
>>>>    
>>>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>>>> index fc082a933d59..8ccbe591b9e2 100644
>>>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>>>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>>>> @@ -1201,19 +1201,21 @@ static bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
>>>>    		drm_dp_sink_supports_dsc(intel_dp->dsc_dpcd);
>>>>    }
>>>>    
>>>> -static bool intel_dp_is_ycbcr420(struct intel_dp *intel_dp,
>>>> -				 const struct intel_crtc_state *crtc_state)
>>>> +static bool intel_dp_is_ycbcr420(const struct intel_crtc_state *crtc_state)
>>>>    {
>>>>    	return crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
>>>>    		(crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444 &&
>>>> -		 intel_dp->dfp.ycbcr_444_to_420);
>>>> +		 crtc_state->dp_dfp_config.ycbcr_444_to_420) ||
>>>> +		(crtc_state->output_format == INTEL_OUTPUT_FORMAT_RGB &&
>>>> +		 crtc_state->dp_dfp_config.ycbcr_444_to_420 &&
>>>> +		 crtc_state->dp_dfp_config.rgb_to_ycbcr);
>>>>    }
>>>>    
>>>>    static int intel_dp_hdmi_compute_bpc(struct intel_dp *intel_dp,
>>>>    				     const struct intel_crtc_state *crtc_state,
>>>>    				     int bpc, bool respect_downstream_limits)
>>>>    {
>>>> -	bool ycbcr420_output = intel_dp_is_ycbcr420(intel_dp, crtc_state);
>>>> +	bool ycbcr420_output = intel_dp_is_ycbcr420(crtc_state);
>>>>    	int clock = crtc_state->hw.adjusted_mode.crtc_clock;
>>>>    
>>>>    	/*
>>>> @@ -1966,6 +1968,30 @@ static bool intel_dp_has_audio(struct intel_encoder *encoder,
>>>>    		return intel_conn_state->force_audio == HDMI_AUDIO_ON;
>>>>    }
>>>>    
>>>> +static void
>>>> +intel_dp_compute_dfp_ycbcr420(struct intel_encoder *encoder,
>>>> +			      struct intel_crtc_state *crtc_state)
>>>> +{
>>>> +	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
>>>> +
>>>> +	if (!drm_dp_is_branch(intel_dp->dpcd))
>>>> +		return;
>>>> +
>>>> +	/* Mode is YCBCR420, output_format is also YCBCR420: Passthrough */
>>>> +	if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420)
>>>> +		return;
>>>> +
>>>> +	/* Mode is YCBCR420, output_format is YCBCR444: Downsample */
>>>> +	if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444) {
>>>> +		crtc_state->dp_dfp_config.ycbcr_444_to_420 = true;
>>>> +		return;
>>>> +	}
>>>> +
>>>> +	/* Mode is YCBCR420, output_format is RGB: Convert to YCBCR444 and Downsample */
>>>> +	crtc_state->dp_dfp_config.rgb_to_ycbcr = true;
>>>> +	crtc_state->dp_dfp_config.ycbcr_444_to_420 = true;
>>>> +}
>>>> +
>>>>    static int
>>>>    intel_dp_compute_output_format(struct intel_encoder *encoder,
>>>>    			       struct intel_crtc_state *crtc_state,
>>>> @@ -1984,7 +2010,10 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
>>>>    
>>>>    	crtc_state->output_format = intel_dp_output_format(connector, ycbcr_420_only);
>>>>    
>>>> -	if (ycbcr_420_only && !intel_dp_is_ycbcr420(intel_dp, crtc_state)) {
>>>> +	if (ycbcr_420_only)
>>>> +		intel_dp_compute_dfp_ycbcr420(encoder, crtc_state);
>>>> +
>>>> +	if (ycbcr_420_only && !intel_dp_is_ycbcr420(crtc_state)) {
>>>>    		drm_dbg_kms(&i915->drm,
>>>>    			    "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");
>>>>    		crtc_state->output_format = INTEL_OUTPUT_FORMAT_RGB;
>>>> @@ -1993,12 +2022,13 @@ intel_dp_compute_output_format(struct intel_encoder *encoder,
>>>>    	ret = intel_dp_compute_link_config(encoder, crtc_state, conn_state,
>>>>    					   respect_downstream_limits);
>>>>    	if (ret) {
>>>> -		if (intel_dp_is_ycbcr420(intel_dp, crtc_state) ||
>>>> +		if (intel_dp_is_ycbcr420(crtc_state) ||
>>>>    		    !connector->base.ycbcr_420_allowed ||
>>>>    		    !drm_mode_is_420_also(info, adjusted_mode))
>>>>    			return ret;
>>>>    
>>>>    		crtc_state->output_format = intel_dp_output_format(connector, true);
>>>> +		intel_dp_compute_dfp_ycbcr420(encoder, crtc_state);
>>>>    		ret = intel_dp_compute_link_config(encoder, crtc_state, conn_state,
>>>>    						   respect_downstream_limits);
>>>>    	}
>>>> @@ -2668,8 +2698,7 @@ void intel_dp_configure_protocol_converter(struct intel_dp *intel_dp,
>>>>    		drm_dbg_kms(&i915->drm, "Failed to %s protocol converter HDMI mode\n",
>>>>    			    str_enable_disable(intel_dp->has_hdmi_sink));
>>>>    
>>>> -	tmp = crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444 &&
>>>> -		intel_dp->dfp.ycbcr_444_to_420 ? DP_CONVERSION_TO_YCBCR420_ENABLE : 0;
>>>> +	tmp = crtc_state->dp_dfp_config.ycbcr_444_to_420 ? DP_CONVERSION_TO_YCBCR420_ENABLE : 0;
>>>>    
>>>>    	if (drm_dp_dpcd_writeb(&intel_dp->aux,
>>>>    			       DP_PROTOCOL_CONVERTER_CONTROL_1, tmp) != 1)
>>>> @@ -2677,7 +2706,7 @@ void intel_dp_configure_protocol_converter(struct intel_dp *intel_dp,
>>>>    			    "Failed to %s protocol converter YCbCr 4:2:0 conversion mode\n",
>>>>    			    str_enable_disable(intel_dp->dfp.ycbcr_444_to_420));
>>>>    
>>>> -	tmp = intel_dp->dfp.rgb_to_ycbcr ?
>>>> +	tmp = crtc_state->dp_dfp_config.rgb_to_ycbcr ?
>>>>    		DP_CONVERSION_BT709_RGB_YCBCR_ENABLE : 0;
>>>>    
>>>>    	if (drm_dp_pcon_convert_rgb_to_ycbcr(&intel_dp->aux, tmp) < 0)
>>>> @@ -2686,7 +2715,6 @@ void intel_dp_configure_protocol_converter(struct intel_dp *intel_dp,
>>>>    			   str_enable_disable(tmp));
>>>>    }
>>>>    
>>>> -
>>>>    bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp)
>>>>    {
>>>>    	u8 dprx = 0;
>>>> @@ -4534,7 +4562,6 @@ intel_dp_update_420(struct intel_dp *intel_dp)
>>>>    {
>>>>    	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
>>>>    	struct intel_connector *connector = intel_dp->attached_connector;
>>>> -	bool is_branch, ycbcr_420_passthrough, ycbcr_444_to_420, rgb_to_ycbcr;
>>>>    
>>>>    	/* No YCbCr output support on gmch platforms */
>>>>    	if (HAS_GMCH(i915))
>>>> @@ -4547,39 +4574,28 @@ intel_dp_update_420(struct intel_dp *intel_dp)
>>>>    	if (IS_IRONLAKE(i915))
>>>>    		return;
>>>>    
>>>> -	is_branch = drm_dp_is_branch(intel_dp->dpcd);
>>>> -	ycbcr_420_passthrough =
>>>> +	if (!drm_dp_is_branch(intel_dp->dpcd)) {
>>>> +		connector->base.ycbcr_420_allowed = true;
>>>> +		return;
>>>> +	}
>>>> +
>>>> +	intel_dp->dfp.ycbcr420_passthrough =
>>>>    		drm_dp_downstream_420_passthrough(intel_dp->dpcd,
>>>>    						  intel_dp->downstream_ports);
>>>> +
>>>>    	/* on-board LSPCON always assumed to support 4:4:4->4:2:0 conversion */
>>>> -	ycbcr_444_to_420 =
>>>> +	intel_dp->dfp.ycbcr_444_to_420 =
>>>>    		dp_to_dig_port(intel_dp)->lspcon.active ||
>>>>    		drm_dp_downstream_444_to_420_conversion(intel_dp->dpcd,
>>>>    							intel_dp->downstream_ports);
>>>> -	rgb_to_ycbcr = drm_dp_downstream_rgb_to_ycbcr_conversion(intel_dp->dpcd,
>>>> -								 intel_dp->downstream_ports,
>>>> -								 DP_DS_HDMI_BT709_RGB_YCBCR_CONV);
>>>> -
>>>> -	if (DISPLAY_VER(i915) >= 11) {
>>>> -		/* Let PCON convert from RGB->YCbCr if possible */
>>>> -		if (is_branch && rgb_to_ycbcr && ycbcr_444_to_420) {
>>>> -			intel_dp->dfp.rgb_to_ycbcr = true;
>>>> -			intel_dp->dfp.ycbcr_444_to_420 = true;
>>>> -			connector->base.ycbcr_420_allowed = true;
>>>> -		} else {
>>>> -		/* Prefer 4:2:0 passthrough over 4:4:4->4:2:0 conversion */
>>>> -			intel_dp->dfp.ycbcr_444_to_420 =
>>>> -				ycbcr_444_to_420 && !ycbcr_420_passthrough;
>>>>    
>>>> -			connector->base.ycbcr_420_allowed =
>>>> -				!is_branch || ycbcr_444_to_420 || ycbcr_420_passthrough;
>>>> -		}
>>>> -	} else {
>>>> -		/* 4:4:4->4:2:0 conversion is the only way */
>>>> -		intel_dp->dfp.ycbcr_444_to_420 = ycbcr_444_to_420;
>>>> +	intel_dp->dfp.rgb_to_ycbcr =
>>>> +		drm_dp_downstream_rgb_to_ycbcr_conversion(intel_dp->dpcd,
>>>> +							  intel_dp->downstream_ports,
>>>> +							  DP_DS_HDMI_BT709_RGB_YCBCR_CONV);
>>>>    
>>>> -		connector->base.ycbcr_420_allowed = ycbcr_444_to_420;
>>>> -	}
>>>> +	if (intel_dp->dfp.ycbcr420_passthrough || intel_dp->dfp.ycbcr_444_to_420)
>>>> +		connector->base.ycbcr_420_allowed = true;
>>>>    
>>>>    	drm_dbg_kms(&i915->drm,
>>>>    		    "[CONNECTOR:%d:%s] RGB->YcbCr conversion? %s, YCbCr 4:2:0 allowed? %s, YCbCr 4:4:4->4:2:0 conversion? %s\n",