This change is required for DSC 1.1 because the current calculation
is for DSC 1.2 and may get a calculated value which is not
recommended by DSC 1.1, for example, the calculated value at 8bpp
becomes 15, not the value of 12 recommened by DSC 1.1.
v2:
- change the if-condition from minor version 2 to 1.
- add comment about first_line_bpg_offset for DSC 1.1.
v3:
- change variable name from rc to vdsc_cfg.
- add Cc
Cc: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
Cc: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
Cc: Juha-Pekka Heikkil <juha-pekka.heikkila@xxxxxxxxx>
Signed-off-by: William Tseng <william.tseng@xxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_vdsc.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
index bd9116d2cd76..c7db3bc94246 100644
--- a/drivers/gpu/drm/i915/display/intel_vdsc.c
+++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
@@ -72,11 +72,19 @@ calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
int qp_bpc_modifier = (bpc - 8) * 2;
u32 res, buf_i, bpp_i;
- if (vdsc_cfg->slice_height >= 8)
- vdsc_cfg->first_line_bpg_offset =
- 12 + DIV_ROUND_UP((9 * min(34, vdsc_cfg->slice_height - 8)), 100);
- else
- vdsc_cfg->first_line_bpg_offset = 2 * (vdsc_cfg->slice_height - 1);
+ if (vdsc_cfg->dsc_version_minor == 1) {
+ /* The recommended and required Values from Table E-2 for DSC1.1 */
+ if (bpp == 8)
+ vdsc_cfg->first_line_bpg_offset = 12;
+ else
+ vdsc_cfg->first_line_bpg_offset = 15;
+ } else {
+ if (vdsc_cfg->slice_height >= 8)
+ vdsc_cfg->first_line_bpg_offset =
+ 12 + DIV_ROUND_UP((9 * min(34, vdsc_cfg->slice_height - 8)), 100);
+ else
+ vdsc_cfg->first_line_bpg_offset = 2 * (vdsc_cfg->slice_height - 1);
+ }
/* Our hw supports only 444 modes as of today */
if (bpp >= 12)
--
2.34.1
