Commit dcd65857 authored by Wenjing Liu's avatar Wenjing Liu Committed by Alex Deucher
Browse files

drm/amd/display: add dc dsc functions to return bpp range for pixel encoding 



[why]
Need to support 6 bpp for 420 pixel encoding only.

[how]
Add a dc function to determine what bpp range can be supported
for given pixel encoding.

Signed-off-by: default avatarWenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: default avatarNikola Cornij <Nikola.Cornij@amd.com>
Acked-by: default avatarLeo Li <sunpeng.li@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 5c7b0f38

drivers/gpu/drm/amd/display/dc/dc_dsc.h

+6 −2
Original line number Diff line number Diff line
@@ -52,8 +52,8 @@ bool dc_dsc_parse_dsc_dpcd(const uint8_t *dpcd_dsc_basic_data, 
bool dc_dsc_compute_bandwidth_range(

		const struct display_stream_compressor *dsc,

		const uint32_t dsc_min_slice_height_override,

		const uint32_t min_kbps,

		const uint32_t max_kbps,

		const uint32_t min_bpp,

		const uint32_t max_bpp,

		const struct dsc_dec_dpcd_caps *dsc_sink_caps,

		const struct dc_crtc_timing *timing,

		struct dc_dsc_bw_range *range);
@@ -65,4 +65,8 @@ bool dc_dsc_compute_config( 
		uint32_t target_bandwidth_kbps,

		const struct dc_crtc_timing *timing,

		struct dc_dsc_config *dsc_cfg);



bool dc_dsc_get_bpp_range_for_pixel_encoding(enum dc_pixel_encoding pixel_enc,

		uint32_t *min_bpp,

		uint32_t *max_bpp);

#endif

drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c

+31 −7
Original line number Diff line number Diff line
@@ -31,16 +31,12 @@ struct dc_dsc_policy { 
	bool use_min_slices_h;

	int max_slices_h; // Maximum available if 0

	int min_sice_height; // Must not be less than 8

	int max_target_bpp;

	int min_target_bpp; // Minimum target bits per pixel

};



const struct dc_dsc_policy dsc_policy = {

	.use_min_slices_h = true, // DSC Policy: Use minimum number of slices that fits the pixel clock

	.max_slices_h = 0, // DSC Policy: Use max available slices (in our case 4 for or 8, depending on the mode)

	.min_sice_height = 108, // DSC Policy: Use slice height recommended by VESA DSC Spreadsheet user guide

	.max_target_bpp = 16,

	.min_target_bpp = 8,

};
@@ -374,7 +370,6 @@ static void get_dsc_bandwidth_range( 
 *        or if it couldn't be applied based on DSC policy.

 */

static bool decide_dsc_target_bpp_x16(

		const struct dc_dsc_policy *policy,

		const struct dsc_enc_caps *dsc_common_caps,

		const int target_bandwidth_kbps,

		const struct dc_crtc_timing *timing,
@@ -382,10 +377,13 @@ static bool decide_dsc_target_bpp_x16( 
{

	bool should_use_dsc = false;

	struct dc_dsc_bw_range range;

	uint32_t min_target_bpp = 0;

	uint32_t max_target_bpp = 0;



	memset(&range, 0, sizeof(range));



	get_dsc_bandwidth_range(policy->min_target_bpp, policy->max_target_bpp,

	dc_dsc_get_bpp_range_for_pixel_encoding(timing->pixel_encoding, &min_target_bpp, &max_target_bpp);

	get_dsc_bandwidth_range(min_target_bpp, max_target_bpp,

			dsc_common_caps, timing, &range);

	if (target_bandwidth_kbps >= range.stream_kbps) {

		/* enough bandwidth without dsc */
@@ -599,7 +597,7 @@ static bool setup_dsc_config( 
		goto done;



	if (target_bandwidth_kbps > 0) {

		is_dsc_possible = decide_dsc_target_bpp_x16(&dsc_policy, &dsc_common_caps, target_bandwidth_kbps, timing, &target_bpp);

		is_dsc_possible = decide_dsc_target_bpp_x16(&dsc_common_caps, target_bandwidth_kbps, timing, &target_bpp);

		dsc_cfg->bits_per_pixel = target_bpp;

	}

	if (!is_dsc_possible)
@@ -906,3 +904,29 @@ bool dc_dsc_compute_config( 
			timing, dsc_min_slice_height_override, dsc_cfg);

	return is_dsc_possible;

}



bool dc_dsc_get_bpp_range_for_pixel_encoding(enum dc_pixel_encoding pixel_enc,

		uint32_t *min_bpp,

		uint32_t *max_bpp)

{

	bool result = true;



	switch (pixel_enc) {

	case PIXEL_ENCODING_RGB:

	case PIXEL_ENCODING_YCBCR444:

	case PIXEL_ENCODING_YCBCR422:

		*min_bpp = 8;

		*max_bpp = 16;

		break;

	case PIXEL_ENCODING_YCBCR420:

		*min_bpp = 6;

		*max_bpp = 16;

		break;

	default:

		*min_bpp = 0;

		*max_bpp = 0;

		result = false;

	}



	return result;

}

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