From: Marijn Suijten marijn.suijten@somainline.org
[ Upstream commit c3a1aabce2d4087255de90100c3dad492e7d925c ]
As per the FIXME this code is entirely duplicate with what is already provided inside drm_dsc_compute_rc_parameters(), supposedly because that function was yielding "incorrect" results while in reality the panel driver(s?) used for testing were providing incorrect parameters.
For example, this code from downstream assumed dsc->bits_per_pixel to contain an integer value, whereas the upstream drm_dsc_config struct stores it with 4 fractional bits. drm_dsc_compute_rc_parameters() already accounts for this feat while the panel driver used for testing [1] wasn't, hence making drm_dsc_compute_rc_parameters() seem like it was returning an incorrect result. Other users of dsc->bits_per_pixel inside dsi_populate_dsc_params() also treat it in the same erroneous way, and will be addressed in a separate patch. In the end, using drm_dsc_compute_rc_parameters() spares both a lot of duplicate code and erratic behaviour.
[1]: https://git.linaro.org/people/vinod.koul/kernel.git/commit/?h=topic/pixel3_5...
Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Abhinav Kumar quic_abhinavk@quicinc.com Signed-off-by: Marijn Suijten marijn.suijten@somainline.org Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Patchwork: https://patchwork.freedesktop.org/patch/508939/ Link: https://lore.kernel.org/r/20221026182824.876933-7-marijn.suijten@somainline.... Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/dsi/dsi_host.c | 64 +++--------------------------- 1 file changed, 6 insertions(+), 58 deletions(-)
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 5e5eb1a10f94..0c80d0797a6a 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -21,6 +21,7 @@
#include <video/mipi_display.h>
+#include <drm/display/drm_dsc_helper.h> #include <drm/drm_of.h>
#include "dsi.h" @@ -1836,14 +1837,6 @@ static char bpg_offset[DSC_NUM_BUF_RANGES] = {
static int dsi_populate_dsc_params(struct drm_dsc_config *dsc) { - int mux_words_size; - int groups_per_line, groups_total; - int min_rate_buffer_size; - int hrd_delay; - int pre_num_extra_mux_bits, num_extra_mux_bits; - int slice_bits; - int data; - int final_value, final_scale; int i;
dsc->rc_model_size = 8192; @@ -1869,11 +1862,11 @@ static int dsi_populate_dsc_params(struct drm_dsc_config *dsc) if (dsc->bits_per_pixel != 8) dsc->initial_offset = 2048; /* bpp = 12 */
- mux_words_size = 48; /* bpc == 8/10 */ - if (dsc->bits_per_component == 12) - mux_words_size = 64; + if (dsc->bits_per_component <= 10) + dsc->mux_word_size = DSC_MUX_WORD_SIZE_8_10_BPC; + else + dsc->mux_word_size = DSC_MUX_WORD_SIZE_12_BPC;
- dsc->mux_word_size = mux_words_size; dsc->initial_xmit_delay = 512; dsc->initial_scale_value = 32; dsc->first_line_bpg_offset = 12; @@ -1885,52 +1878,7 @@ static int dsi_populate_dsc_params(struct drm_dsc_config *dsc) dsc->rc_quant_incr_limit0 = 11; dsc->rc_quant_incr_limit1 = 11;
- /* FIXME: need to call drm_dsc_compute_rc_parameters() so that rest of - * params are calculated - */ - groups_per_line = DIV_ROUND_UP(dsc->slice_width, 3); - dsc->slice_chunk_size = DIV_ROUND_UP(dsc->slice_width * dsc->bits_per_pixel, 8); - - /* rbs-min */ - min_rate_buffer_size = dsc->rc_model_size - dsc->initial_offset + - dsc->initial_xmit_delay * dsc->bits_per_pixel + - groups_per_line * dsc->first_line_bpg_offset; - - hrd_delay = DIV_ROUND_UP(min_rate_buffer_size, dsc->bits_per_pixel); - - dsc->initial_dec_delay = hrd_delay - dsc->initial_xmit_delay; - - dsc->initial_scale_value = 8 * dsc->rc_model_size / - (dsc->rc_model_size - dsc->initial_offset); - - slice_bits = 8 * dsc->slice_chunk_size * dsc->slice_height; - - groups_total = groups_per_line * dsc->slice_height; - - data = dsc->first_line_bpg_offset * 2048; - - dsc->nfl_bpg_offset = DIV_ROUND_UP(data, (dsc->slice_height - 1)); - - pre_num_extra_mux_bits = 3 * (mux_words_size + (4 * dsc->bits_per_component + 4) - 2); - - num_extra_mux_bits = pre_num_extra_mux_bits - (mux_words_size - - ((slice_bits - pre_num_extra_mux_bits) % mux_words_size)); - - data = 2048 * (dsc->rc_model_size - dsc->initial_offset + num_extra_mux_bits); - dsc->slice_bpg_offset = DIV_ROUND_UP(data, groups_total); - - data = dsc->initial_xmit_delay * dsc->bits_per_pixel; - final_value = dsc->rc_model_size - data + num_extra_mux_bits; - dsc->final_offset = final_value; - - final_scale = 8 * dsc->rc_model_size / (dsc->rc_model_size - final_value); - - data = (final_scale - 9) * (dsc->nfl_bpg_offset + dsc->slice_bpg_offset); - dsc->scale_increment_interval = (2048 * dsc->final_offset) / data; - - dsc->scale_decrement_interval = groups_per_line / (dsc->initial_scale_value - 8); - - return 0; + return drm_dsc_compute_rc_parameters(dsc); }
static int dsi_host_parse_dt(struct msm_dsi_host *msm_host)