@@ -335,6 +335,132 @@ static int get_column_index_for_rc_params(u8 bits_per_component)
}
}
+static int intel_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg)
+{
+ unsigned long groups_per_line = 0;
+ unsigned long groups_total = 0;
+ unsigned long num_extra_mux_bits = 0;
+ unsigned long slice_bits = 0;
+ unsigned long hrd_delay = 0;
+ unsigned long final_scale = 0;
+ unsigned long rbs_min = 0;
+
+ /* RC_MODEL_SIZE is a constant across all configurations */
+ vdsc_cfg->rc_model_size = DSC_RC_MODEL_SIZE_CONST;
+ /* Number of groups used to code each line of a slice */
+ groups_per_line = DIV_ROUND_UP(vdsc_cfg->slice_width,
+ DP_DSC_RC_PIXELS_PER_GROUP);
+
+ /* chunksize in Bytes */
+ vdsc_cfg->slice_chunk_size = DIV_ROUND_UP(vdsc_cfg->slice_width *
+ vdsc_cfg->bits_per_pixel, 8);
+
+ if (vdsc_cfg->convert_rgb)
+ num_extra_mux_bits = 3 *
+ (vdsc_cfg->mux_word_size +
+ (4 * vdsc_cfg->bits_per_component + 4) - 2);
+ else
+ num_extra_mux_bits = 3 * vdsc_cfg->mux_word_size +
+ (4 * vdsc_cfg->bits_per_component + 4) +
+ 2 * (4 * vdsc_cfg->bits_per_component) - 2;
+ /* Number of bits in one Slice */
+ slice_bits = 8 * vdsc_cfg->slice_chunk_size * vdsc_cfg->slice_height;
+
+ while ((num_extra_mux_bits > 0) &&
+ ((slice_bits - num_extra_mux_bits) % vdsc_cfg->mux_word_size))
+ num_extra_mux_bits--;
+
+ if (groups_per_line < vdsc_cfg->initial_scale_value - 8)
+ vdsc_cfg->initial_scale_value = groups_per_line + 8;
+
+ /* scale_decrement_interval calculation according to DSC spec 1.11 */
+ if (vdsc_cfg->initial_scale_value > 8)
+ vdsc_cfg->scale_decrement_interval = groups_per_line /
+ (8 * vdsc_cfg->initial_scale_value - 8);
+ else
+ vdsc_cfg->scale_decrement_interval =
+ DP_DSC_SCALE_DECREMENT_INTERVAL_MAX;
+
+ vdsc_cfg->final_offset = vdsc_cfg->rc_model_size -
+ (vdsc_cfg->initial_xmit_delay *
+ vdsc_cfg->bits_per_pixel) + num_extra_mux_bits;
+
+ if (vdsc_cfg->final_offset >= vdsc_cfg->rc_model_size) {
+ DRM_ERROR("FinalOfs < RcModelSze for this InitialXmitDelay\n");
+ return -1;
+ }
+
+ final_scale = (vdsc_cfg->rc_model_size << 3) /
+ (vdsc_cfg->rc_model_size - vdsc_cfg->final_offset);
+ if (vdsc_cfg->slice_height > 1)
+ /*
+ * NflBpgOffset is 16 bit value with 11 fractional bits
+ * hence we multiply by 2^11 for preserving the
+ * fractional part
+ */
+ vdsc_cfg->nfl_bpg_offset = DIV_ROUND_UP(
+ (vdsc_cfg->first_line_bpg_offset << 11),
+ (vdsc_cfg->slice_height - 1));
+ else
+ vdsc_cfg->nfl_bpg_offset = 0;
+
+ /* 2^16 - 1 */
+ if (vdsc_cfg->nfl_bpg_offset > 65535) {
+ DRM_ERROR("NflBpgOffset is too large for this slice height\n");
+ return -1;
+ }
+
+ /* Number of groups used to code the entire slice */
+ groups_total = groups_per_line * vdsc_cfg->slice_height;
+
+ /* slice_bpg_offset is 16 bit value with 11 fractional bits */
+ vdsc_cfg->slice_bpg_offset = DIV_ROUND_UP(
+ ((vdsc_cfg->rc_model_size - vdsc_cfg->initial_offset +
+ num_extra_mux_bits) << 11), groups_total);
+
+ if (final_scale > 0x9) {
+ /*
+ * ScaleIncrementInterval =
+ * finaloffset/((NflBpgOffset + SliceBpgOffset)*8(finalscale - 1.125))
+ * as (NflBpgOffset + SliceBpgOffset) has 11 bit fractional value,
+ * we need divide by 2^11 from pstDscCfg values
+ */
+ vdsc_cfg->scale_increment_interval =
+ (vdsc_cfg->final_offset * (1 << 11)) /
+ ((vdsc_cfg->nfl_bpg_offset +
+ vdsc_cfg->slice_bpg_offset)*
+ (final_scale - 9));
+ } else {
+ /*
+ * If finalScaleValue is less than or equal to 9, a value of 0 should
+ * be used to disable the scale increment at the end of the slice
+ */
+ vdsc_cfg->scale_increment_interval = 0;
+ }
+
+ if (vdsc_cfg->scale_increment_interval > 65535) {
+ DRM_ERROR("ScaleIncrementInterval is large for slice height\n");
+ return -1;
+ }
+
+ /*
+ * DSC spec mentions that bits_per_pixel specifies the target
+ * bits/pixel (bpp) rate that is used by the encoder,
+ * in steps of 1/16 of a bit per pixel
+ */
+ rbs_min = vdsc_cfg->rc_model_size - vdsc_cfg->initial_offset +
+ DIV_ROUND_UP(vdsc_cfg->initial_xmit_delay *
+ vdsc_cfg->bits_per_pixel, 16) +
+ groups_per_line * vdsc_cfg->first_line_bpg_offset;
+
+ hrd_delay = DIV_ROUND_UP((rbs_min * 16), vdsc_cfg->bits_per_pixel);
+ vdsc_cfg->rc_bits = (hrd_delay * vdsc_cfg->bits_per_pixel) / 16;
+ vdsc_cfg->initial_dec_delay = hrd_delay - vdsc_cfg->initial_xmit_delay;
+
+ return 0;
+}
+
+
int intel_dp_compute_dsc_params(struct intel_dp *intel_dp,
struct intel_crtc_state *pipe_config)
{
@@ -455,5 +581,8 @@ int intel_dp_compute_dsc_params(struct intel_dp *intel_dp,
vdsc_cfg->initial_scale_value = (vdsc_cfg->rc_model_size << 3) /
(vdsc_cfg->rc_model_size - vdsc_cfg->initial_offset);
+ if (intel_compute_rc_parameters(vdsc_cfg) < 0)
+ return -1;
+
return 0;
}