@@ -6,6 +6,7 @@
* Manasi Navare <manasi.d.navare@intel.com>
*/
#include <linux/limits.h>
+#include <linux/minmax.h>
#include <drm/display/drm_dsc_helper.h>
@@ -80,13 +81,19 @@ calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
int bpc = vdsc_cfg->bits_per_component;
int bpp = vdsc_cfg->bits_per_pixel >> 4;
int qp_bpc_modifier = (bpc - 8) * 2;
+ int uncompressed_bpg_rate;
+ int first_line_bpg_offset;
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);
+ first_line_bpg_offset =
+ 12 + (9 * min(34, vdsc_cfg->slice_height - 8)) / 100;
else
- vdsc_cfg->first_line_bpg_offset = 2 * (vdsc_cfg->slice_height - 1);
+ first_line_bpg_offset = 2 * (vdsc_cfg->slice_height - 1);
+
+ uncompressed_bpg_rate = (3 * bpc + (vdsc_cfg->convert_rgb ? 0 : 2)) * 3;
+ vdsc_cfg->first_line_bpg_offset = clamp(first_line_bpg_offset, 0,
+ uncompressed_bpg_rate - 3 * bpp);
/*
* According to DSC 1.2 spec in Section 4.1 if native_420 is set: