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| author | Marijn Suijten <marijn.suijten@somainline.org> | 2022-10-26 20:28:15 +0200 |
|---|---|---|
| committer | Dmitry Baryshkov <dmitry.baryshkov@linaro.org> | 2022-11-04 17:39:41 +0300 |
| commit | 01a907980e0be3310f18c7d4955968f3b28e7147 (patch) | |
| tree | 6766db9175a9fa6c64dc56815e29fccbafd28d23 /drivers/gpu/drm/msm | |
| parent | 572e9fd6d14a4568ee731c84e54ceaa243c82408 (diff) | |
| download | linux-stable-01a907980e0be3310f18c7d4955968f3b28e7147.tar.gz linux-stable-01a907980e0be3310f18c7d4955968f3b28e7147.tar.bz2 linux-stable-01a907980e0be3310f18c7d4955968f3b28e7147.zip | |
drm/msm/dsi: Remove useless math in DSC calculations
Multiplying a value by 2 and adding 1 to it always results in a value
that is uneven, and that 1 gets truncated immediately when performing
integer division by 2 again. There is no "rounding" possible here.
After that target_bpp_x16 is used to store a multiplication of
bits_per_pixel by 16 which is only ever read to immediately be divided
by 16 again, and is elided in much the same way.
Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data")
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Patchwork: https://patchwork.freedesktop.org/patch/508932/
Link: https://lore.kernel.org/r/20221026182824.876933-2-marijn.suijten@somainline.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Diffstat (limited to 'drivers/gpu/drm/msm')
| -rw-r--r-- | drivers/gpu/drm/msm/dsi/dsi_host.c | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 7fbf391c024f..8026fe65bff6 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1762,7 +1762,6 @@ static int dsi_populate_dsc_params(struct drm_dsc_config *dsc) int hrd_delay; int pre_num_extra_mux_bits, num_extra_mux_bits; int slice_bits; - int target_bpp_x16; int data; int final_value, final_scale; int i; @@ -1842,14 +1841,7 @@ static int dsi_populate_dsc_params(struct drm_dsc_config *dsc) data = 2048 * (dsc->rc_model_size - dsc->initial_offset + num_extra_mux_bits); dsc->slice_bpg_offset = DIV_ROUND_UP(data, groups_total); - /* bpp * 16 + 0.5 */ - data = dsc->bits_per_pixel * 16; - data *= 2; - data++; - data /= 2; - target_bpp_x16 = data; - - data = (dsc->initial_xmit_delay * target_bpp_x16) / 16; + 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; |