From: Vandita Kulkarni <vandita.kulkarni@xxxxxxxxx>
Consider the fractional bpp while reading the qp values.
v2: Use helpers for fractional, integral bits of bits_per_pixel. (Suraj)
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@xxxxxxxxx>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
---
.../gpu/drm/i915/display/intel_qp_tables.c | 3 ---
drivers/gpu/drm/i915/display/intel_vdsc.c | 25 +++++++++++++++----
2 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_qp_tables.c b/drivers/gpu/drm/i915/display/intel_qp_tables.c
index 543cdc46aa1d..600c815e37e4 100644
--- a/drivers/gpu/drm/i915/display/intel_qp_tables.c
+++ b/drivers/gpu/drm/i915/display/intel_qp_tables.c
@@ -34,9 +34,6 @@
* These qp tables are as per the C model
* and it has the rows pointing to bpps which increment
* in steps of 0.5
- * We do not support fractional bpps as of today,
- * hence we would skip the fractional bpps during
- * our references for qp calclulations.
*/
static const u8 rc_range_minqp444_8bpc[DSC_NUM_BUF_RANGES][RC_RANGE_QP444_8BPC_MAX_NUM_BPP] = {
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
index 1bd9391a6f5a..2c19078fbce8 100644
--- a/drivers/gpu/drm/i915/display/intel_vdsc.c
+++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
@@ -78,8 +78,8 @@ intel_vdsc_set_min_max_qp(struct drm_dsc_config *vdsc_cfg, int buf,
static void
calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
{
+ int bpp = intel_fractional_bpp_from_x16(vdsc_cfg->bits_per_pixel);
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;
@@ -149,7 +149,13 @@ calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
static const s8 ofs_und8[] = {
10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10, -10, -12, -12, -12
};
-
+ /*
+ * For 420 format since bits_per_pixel (bpp) is set to target bpp * 2,
+ * QP table values for target bpp 4.0 to 4.4375 (rounded to 4.0) are
+ * actually for bpp 8 to 8.875 (rounded to 4.0 * 2 i.e 8).
+ * Similarly values for target bpp 4.5 to 4.8375 (rounded to 4.5)
+ * are for bpp 9 to 9.875 (rounded to 4.5 * 2 i.e 9), and so on.
+ */
bpp_i = bpp - 8;
for (buf_i = 0; buf_i < DSC_NUM_BUF_RANGES; buf_i++) {
u8 range_bpg_offset;
@@ -179,6 +185,9 @@ calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
range_bpg_offset & DSC_RANGE_BPG_OFFSET_MASK;
}
} else {
+ /* fractional bpp part * 10000 (for precision up to 4 decimal places) */
+ int fractional_bits = intel_fractional_bpp_decimal(vdsc_cfg->bits_per_pixel);
+
static const s8 ofs_und6[] = {
0, -2, -2, -4, -6, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12
};
@@ -192,7 +201,14 @@ calculate_rc_params(struct drm_dsc_config *vdsc_cfg)
10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10, -10, -12, -12, -12
};
- bpp_i = (2 * (bpp - 6));
+ /*
+ * QP table rows have values in increment of 0.5.
+ * So 6.0 bpp to 6.4375 will have index 0, 6.5 to 6.9375 will have index 1,
+ * and so on.
+ * 0.5 fractional part with 4 decimal precision becomes 5000
+ */
+ bpp_i = ((bpp - 6) + (fractional_bits < 5000 ? 0 : 1));
+
for (buf_i = 0; buf_i < DSC_NUM_BUF_RANGES; buf_i++) {
u8 range_bpg_offset;
@@ -280,8 +296,7 @@ int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
/* Gen 11 does not support VBR */
vdsc_cfg->vbr_enable = false;
- /* Gen 11 only supports integral values of bpp */
- vdsc_cfg->bits_per_pixel = compressed_bpp << 4;
+ vdsc_cfg->bits_per_pixel = pipe_config->dsc.compressed_bpp_x16;
/*
* According to DSC 1.2 specs in Section 4.1 if native_420 is set
--
2.25.1
