[Intel-gfx] [PATCH 13/13] drm/i915/dp: Use consistent name for link bpp and compressed bpp

Nautiyal, Ankit K ankit.k.nautiyal at intel.com
Wed Apr 26 06:10:41 UTC 2023


On 4/24/2023 6:34 PM, Ville Syrjälä wrote:
> On Fri, Mar 31, 2023 at 03:46:13PM +0530, Ankit Nautiyal wrote:
>> Currently there are many places where we use output_bpp for link bpp and
>> compressed bpp.
>> Lets use consistent naming:
>> output_bpp : The intermediate value taking into account the
>> output_format chroma subsampling.
>> compressed_bpp : target bpp for the DSC encoder.
>> link_bpp : final bpp used in the link.
>>
>> For 444 sampling without DSC:
>> link_bpp = output_bpp = pipe_bpp
>>
>> For 420 sampling without DSC:
>> output_bpp = pipe_bpp / 2
>> link_bpp = output_bpp
>>
>> For 444 sampling with DSC:
>> output_bpp = pipe_bpp
>> link_bpp = compressed_bpp, computed with output_bpp (i.e. pipe_bpp in
>> this case)
>>
>> For 420 sampling with DSC:
>> output_bpp = pipe_bpp/2
>> link_bpp = compressed_bpp, computed with output_bpp
>>
>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_dp.c     | 84 ++++++++++-----------
>>   drivers/gpu/drm/i915/display/intel_dp.h     | 14 ++--
>>   drivers/gpu/drm/i915/display/intel_dp_mst.c | 22 +++---
>>   3 files changed, 60 insertions(+), 60 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 63f3f6ff2cad..22b98653d539 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -710,13 +710,13 @@ u32 intel_dp_dsc_nearest_valid_bpp(struct drm_i915_private *i915, u32 bpp, u32 p
>>   	return bits_per_pixel;
>>   }
>>   
>> -u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
>> -				u32 link_clock, u32 lane_count,
>> -				u32 mode_clock, u32 mode_hdisplay,
>> -				bool bigjoiner,
>> -				enum intel_output_format output_format,
>> -				u32 pipe_bpp,
>> -				u32 timeslots)
>> +u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
>> +					u32 link_clock, u32 lane_count,
>> +					u32 mode_clock, u32 mode_hdisplay,
>> +					bool bigjoiner,
>> +					enum intel_output_format output_format,
>> +					u32 pipe_bpp,
>> +					u32 timeslots)
>>   {
>>   	u32 bits_per_pixel, max_bpp_small_joiner_ram;
>>   
>> @@ -1118,7 +1118,7 @@ intel_dp_mode_valid(struct drm_connector *_connector,
>>   	int target_clock = mode->clock;
>>   	int max_rate, mode_rate, max_lanes, max_link_clock;
>>   	int max_dotclk = dev_priv->max_dotclk_freq;
>> -	u16 dsc_max_output_bpp = 0;
>> +	u16 dsc_max_compressed_bpp = 0;
>>   	u8 dsc_slice_count = 0;
>>   	enum drm_mode_status status;
>>   	bool dsc = false, bigjoiner = false;
>> @@ -1173,21 +1173,21 @@ intel_dp_mode_valid(struct drm_connector *_connector,
>>   		 * integer value since we support only integer values of bpp.
>>   		 */
>>   		if (intel_dp_is_edp(intel_dp)) {
>> -			dsc_max_output_bpp =
>> +			dsc_max_compressed_bpp =
>>   				drm_edp_dsc_sink_output_bpp(intel_dp->dsc_dpcd) >> 4;
> Renaming that as well would be nice, as a separate patch.

Agreed. Perhaps drm_dp_dsc_sink_compressed_bpp for both dp/edp.

>
>>   			dsc_slice_count =
>>   				drm_dp_dsc_sink_max_slice_count(intel_dp->dsc_dpcd,
>>   								true);
>>   		} else if (drm_dp_sink_supports_fec(intel_dp->fec_capable)) {
>> -			dsc_max_output_bpp =
>> -				intel_dp_dsc_get_output_bpp(dev_priv,
>> -							    max_link_clock,
>> -							    max_lanes,
>> -							    target_clock,
>> -							    mode->hdisplay,
>> -							    bigjoiner,
>> -							    output_format,
>> -							    pipe_bpp, 64) >> 4;
>> +			dsc_max_compressed_bpp =
>> +				intel_dp_dsc_get_max_compressed_bpp(dev_priv,
>> +								    max_link_clock,
>> +								    max_lanes,
>> +								    target_clock,
>> +								    mode->hdisplay,
>> +								    bigjoiner,
>> +								    output_format,
>> +								    pipe_bpp, 64) >> 4;
>>   			dsc_slice_count =
>>   				intel_dp_dsc_get_slice_count(intel_dp,
>>   							     target_clock,
>> @@ -1195,7 +1195,7 @@ intel_dp_mode_valid(struct drm_connector *_connector,
>>   							     bigjoiner);
>>   		}
>>   
>> -		dsc = dsc_max_output_bpp && dsc_slice_count;
>> +		dsc = dsc_max_compressed_bpp && dsc_slice_count;
>>   	}
>>   
>>   	/*
>> @@ -1477,9 +1477,9 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp,
>>   	int mode_rate, link_rate, link_avail;
>>   
>>   	for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) {
>> -		int output_bpp = intel_dp_output_bpp(pipe_config->output_format, bpp);
>> +		int link_bpp = intel_dp_output_bpp(pipe_config->output_format, bpp);
>>   
>> -		mode_rate = intel_dp_link_required(clock, output_bpp);
>> +		mode_rate = intel_dp_link_required(clock, link_bpp);
>>   
>>   		for (i = 0; i < intel_dp->num_common_rates; i++) {
>>   			link_rate = intel_dp_common_rate(intel_dp, i);
>> @@ -1728,21 +1728,21 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
>>   			drm_dp_dsc_sink_max_slice_count(intel_dp->dsc_dpcd,
>>   							true);
>>   	} else {
>> -		u16 dsc_max_output_bpp = 0;
>> +		u16 dsc_max_compressed_bpp = 0;
>>   		u8 dsc_dp_slice_count;
>>   
>>   		if (compute_pipe_bpp) {
>> -			dsc_max_output_bpp =
>> -				intel_dp_dsc_get_output_bpp(dev_priv,
>> -							    pipe_config->port_clock,
>> -							    pipe_config->lane_count,
>> -							    adjusted_mode->crtc_clock,
>> -							    adjusted_mode->crtc_hdisplay,
>> -							    pipe_config->bigjoiner_pipes,
>> -							    pipe_config->output_format,
>> -							    pipe_bpp,
>> -							    timeslots);
>> -			if (!dsc_max_output_bpp) {
>> +			dsc_max_compressed_bpp =
>> +				intel_dp_dsc_get_max_compressed_bpp(dev_priv,
>> +								    pipe_config->port_clock,
>> +								    pipe_config->lane_count,
>> +								    adjusted_mode->crtc_clock,
>> +								    adjusted_mode->crtc_hdisplay,
>> +								    pipe_config->bigjoiner_pipes,
>> +								    pipe_config->output_format,
>> +								    pipe_bpp,
>> +								    timeslots);
>> +			if (!dsc_max_compressed_bpp) {
>>   				drm_dbg_kms(&dev_priv->drm,
>>   					    "Compressed BPP not supported\n");
>>   				return -EINVAL;
>> @@ -1767,7 +1767,7 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
>>   		 */
>>   		if (compute_pipe_bpp) {
>>   			pipe_config->dsc.compressed_bpp = min_t(u16,
>> -								dsc_max_output_bpp >> 4,
>> +								dsc_max_compressed_bpp >> 4,
>>   								pipe_config->pipe_bpp);
> Should that be min(max_compressed_bpp>>4, output_bpp) ?

Hmm i think the idea here is that the pixel data after compression 
should be min than the pixel data before compression.

With sub-sampling the effective pixel data is less than that without 
sub-sampling, so here output_bpp should be the right thing.

Regards,

Ankit

>
> The rest makes sense
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
>>   		}
>>   		pipe_config->dsc.slice_count = dsc_dp_slice_count;
>> @@ -2143,7 +2143,7 @@ static bool can_enable_drrs(struct intel_connector *connector,
>>   static void
>>   intel_dp_drrs_compute_config(struct intel_connector *connector,
>>   			     struct intel_crtc_state *pipe_config,
>> -			     int output_bpp)
>> +			     int link_bpp)
>>   {
>>   	struct drm_i915_private *i915 = to_i915(connector->base.dev);
>>   	const struct drm_display_mode *downclock_mode =
>> @@ -2168,7 +2168,7 @@ intel_dp_drrs_compute_config(struct intel_connector *connector,
>>   	if (pipe_config->splitter.enable)
>>   		pixel_clock /= pipe_config->splitter.link_count;
>>   
>> -	intel_link_compute_m_n(output_bpp, pipe_config->lane_count, pixel_clock,
>> +	intel_link_compute_m_n(link_bpp, pipe_config->lane_count, pixel_clock,
>>   			       pipe_config->port_clock, &pipe_config->dp_m2_n2,
>>   			       pipe_config->fec_enable);
>>   
>> @@ -2265,7 +2265,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>>   	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
>>   	const struct drm_display_mode *fixed_mode;
>>   	struct intel_connector *connector = intel_dp->attached_connector;
>> -	int ret = 0, output_bpp;
>> +	int ret = 0, link_bpp;
>>   
>>   	if (HAS_PCH_SPLIT(dev_priv) && !HAS_DDI(dev_priv) && encoder->port != PORT_A)
>>   		pipe_config->has_pch_encoder = true;
>> @@ -2315,10 +2315,10 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>>   		intel_dp_limited_color_range(pipe_config, conn_state);
>>   
>>   	if (pipe_config->dsc.compression_enable)
>> -		output_bpp = pipe_config->dsc.compressed_bpp;
>> +		link_bpp = pipe_config->dsc.compressed_bpp;
>>   	else
>> -		output_bpp = intel_dp_output_bpp(pipe_config->output_format,
>> -						 pipe_config->pipe_bpp);
>> +		link_bpp = intel_dp_output_bpp(pipe_config->output_format,
>> +					       pipe_config->pipe_bpp);
>>   
>>   	if (intel_dp->mso_link_count) {
>>   		int n = intel_dp->mso_link_count;
>> @@ -2342,7 +2342,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>>   
>>   	intel_dp_audio_compute_config(encoder, pipe_config, conn_state);
>>   
>> -	intel_link_compute_m_n(output_bpp,
>> +	intel_link_compute_m_n(link_bpp,
>>   			       pipe_config->lane_count,
>>   			       adjusted_mode->crtc_clock,
>>   			       pipe_config->port_clock,
>> @@ -2358,7 +2358,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>>   
>>   	intel_vrr_compute_config(pipe_config, conn_state);
>>   	intel_psr_compute_config(intel_dp, pipe_config, conn_state);
>> -	intel_dp_drrs_compute_config(connector, pipe_config, output_bpp);
>> +	intel_dp_drrs_compute_config(connector, pipe_config, link_bpp);
>>   	intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
>>   	intel_dp_compute_hdr_metadata_infoframe_sdp(intel_dp, pipe_config, conn_state);
>>   
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
>> index 856172bfa13e..42b98546c140 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.h
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
>> @@ -103,13 +103,13 @@ void intel_read_dp_sdp(struct intel_encoder *encoder,
>>   		       unsigned int type);
>>   bool intel_digital_port_connected(struct intel_encoder *encoder);
>>   int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc);
>> -u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *i915,
>> -				u32 link_clock, u32 lane_count,
>> -				u32 mode_clock, u32 mode_hdisplay,
>> -				bool bigjoiner,
>> -				enum intel_output_format output_format,
>> -				u32 pipe_bpp,
>> -				u32 timeslots);
>> +u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
>> +					u32 link_clock, u32 lane_count,
>> +					u32 mode_clock, u32 mode_hdisplay,
>> +					bool bigjoiner,
>> +					enum intel_output_format output_format,
>> +					u32 pipe_bpp,
>> +					u32 timeslots);
>>   u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp,
>>   				int mode_clock, int mode_hdisplay,
>>   				bool bigjoiner);
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> index fec3f310fc9b..7b91c6c9c286 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> @@ -869,7 +869,7 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
>>   	int max_rate, mode_rate, max_lanes, max_link_clock;
>>   	int ret;
>>   	bool dsc = false, bigjoiner = false;
>> -	u16 dsc_max_output_bpp = 0;
>> +	u16 dsc_max_compressed_bpp = 0;
>>   	u8 dsc_slice_count = 0;
>>   	int target_clock = mode->clock;
>>   
>> @@ -923,15 +923,15 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
>>   		int pipe_bpp = intel_dp_dsc_compute_bpp(intel_dp, U8_MAX);
>>   
>>   		if (drm_dp_sink_supports_fec(intel_dp->fec_capable)) {
>> -			dsc_max_output_bpp =
>> -				intel_dp_dsc_get_output_bpp(dev_priv,
>> -							    max_link_clock,
>> -							    max_lanes,
>> -							    target_clock,
>> -							    mode->hdisplay,
>> -							    bigjoiner,
>> -							    INTEL_OUTPUT_FORMAT_RGB,
>> -							    pipe_bpp, 64) >> 4;
>> +			dsc_max_compressed_bpp =
>> +				intel_dp_dsc_get_max_compressed_bpp(dev_priv,
>> +								    max_link_clock,
>> +								    max_lanes,
>> +								    target_clock,
>> +								    mode->hdisplay,
>> +								    bigjoiner,
>> +								    INTEL_OUTPUT_FORMAT_RGB,
>> +								    pipe_bpp, 64) >> 4;
>>   			dsc_slice_count =
>>   				intel_dp_dsc_get_slice_count(intel_dp,
>>   							     target_clock,
>> @@ -939,7 +939,7 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
>>   							     bigjoiner);
>>   		}
>>   
>> -		dsc = dsc_max_output_bpp && dsc_slice_count;
>> +		dsc = dsc_max_compressed_bpp && dsc_slice_count;
>>   	}
>>   
>>   	/*
>> -- 
>> 2.25.1


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