[Intel-gfx] [PATCH 1/2] drm/i915/dsc: Move rc param calculation for native_420

Suraj Kandpal suraj.kandpal at intel.com
Tue May 23 10:16:50 UTC 2023


Move rc_param calculation for native_420 into calculate_rc_parameter.

Cc: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
---
 drivers/gpu/drm/i915/display/intel_vdsc.c | 28 +++++++++++++----------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
index bd9116d2cd76..c64a38363e02 100644
--- a/drivers/gpu/drm/i915/display/intel_vdsc.c
+++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
@@ -78,6 +78,22 @@ calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
 	else
 		vdsc_cfg->first_line_bpg_offset = 2 * (vdsc_cfg->slice_height - 1);
 
+	/* According to DSC 1.2 specs in Section 4.1 if native_420 is set:
+	 * -second_line_bpg_offset is 12 in general and equal to 2*(slice_height-1) if slice
+	 * height < 8.
+	 * -second_line_offset_adj is 512 as shown by emperical values to yeild best chroma
+	 * preservation in second line.
+	 */
+	if (vdsc_cfg->native_420) {
+		if (vdsc_cfg->slice_height >= 8)
+			vdsc_cfg->second_line_bpg_offset = 12;
+		else
+			vdsc_cfg->second_line_bpg_offset =
+				2 * (vdsc_cfg->slice_height - 1);
+
+		vdsc_cfg->second_line_offset_adj = 512;
+	}
+
 	/* Our hw supports only 444 modes as of today */
 	if (bpp >= 12)
 		vdsc_cfg->initial_offset = 2048;
@@ -192,24 +208,12 @@ int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
 	/*
 	 * According to DSC 1.2 specs in Section 4.1 if native_420 is set:
 	 * -We need to double the current bpp.
-	 * -second_line_bpg_offset is 12 in general and equal to 2*(slice_height-1) if slice
-	 * height < 8.
-	 * -second_line_offset_adj is 512 as shown by emperical values to yeild best chroma
-	 * preservation in second line.
 	 * -nsl_bpg_offset is calculated as second_line_offset/slice_height -1 then rounded
 	 * up to 16 fractional bits, we left shift second line offset by 11 to preserve 11
 	 * fractional bits.
 	 */
 	if (vdsc_cfg->native_420) {
 		vdsc_cfg->bits_per_pixel <<= 1;
-
-		if (vdsc_cfg->slice_height >= 8)
-			vdsc_cfg->second_line_bpg_offset = 12;
-		else
-			vdsc_cfg->second_line_bpg_offset =
-				2 * (vdsc_cfg->slice_height - 1);
-
-		vdsc_cfg->second_line_offset_adj = 512;
 		vdsc_cfg->nsl_bpg_offset = DIV_ROUND_UP(vdsc_cfg->second_line_bpg_offset << 11,
 							vdsc_cfg->slice_height - 1);
 	}
-- 
2.25.1



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