This is a note to let you know that I've just added the patch titled
drm/msm/dpu: Fix slice_last_group_size calculation
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-msm-dpu-fix-slice_last_group_size-calculation.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e0f9dfbcf9658c1f0c473579575a595dfd94f73c
Author: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
Date: Wed May 24 10:45:20 2023 -0700
drm/msm/dpu: Fix slice_last_group_size calculation
[ Upstream commit c223059e6f8340f7eac2319470984cbfc39c433b ]
Correct the math for slice_last_group_size so that it matches the
calculations downstream.
Fixes: c110cfd1753e ("drm/msm/disp/dpu1: Add support for DSC")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Reviewed-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
Patchwork: https://patchwork.freedesktop.org/patch/539269/
Link: https://lore.kernel.org/r/20230329-rfc-msm-dsc-helper-v14-7-bafc7be95691@xxxxxxxxxxx
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.c
index 4e1396575e6aa..c3c70ba61c1c4 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.c
@@ -54,9 +54,10 @@ static void dpu_hw_dsc_config(struct dpu_hw_dsc *hw_dsc,
if (is_cmd_mode)
initial_lines += 1;
- slice_last_group_size = 3 - (dsc->slice_width % 3);
+ slice_last_group_size = (dsc->slice_width + 2) % 3;
+
data = (initial_lines << 20);
- data |= ((slice_last_group_size - 1) << 18);
+ data |= (slice_last_group_size << 18);
/* bpp is 6.4 format, 4 LSBs bits are for fractional part */
data |= (dsc->bits_per_pixel << 8);
data |= (dsc->block_pred_enable << 7);
