From: Marijn Suijten marijn.suijten@somainline.org
[ Upstream commit bc6b6ff8135c4b96787eda88f3baf653939a75ce ]
According to downstream the value to use for WORD_COUNT is bytes_per_pkt, which denotes the number of bytes in a packet based on how many slices have been configured by the panel driver times the width of a slice times the number of bytes per pixel.
The DSC panels seen thus far use one byte per pixel, only one slice per packet, and a slice width of half the panel width leading to the desired bytes_per_pkt+1 value to be equal to hdisplay/2+1. This however isn't the case anymore for panels that configure two slices per packet, where the value should now be hdisplay+1.
Note that the aforementioned panel (on a Sony Xperia XZ3, sdm845) with slice_count=1 has also been tested to successfully accept slice_count=2, which would have shown corrupted output previously.
Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration") Signed-off-by: Marijn Suijten marijn.suijten@somainline.org Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Reviewed-by: Abhinav Kumar quic_abhinavk@quicinc.com Patchwork: https://patchwork.freedesktop.org/patch/515694/ Link: https://lore.kernel.org/r/20221221231943.1961117-3-marijn.suijten@somainline... Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Stable-dep-of: 155fa3a91d64 ("drm/msm/dsi: Remove incorrect references to slice_count") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index f167a45f1fbdd..5ab5e872c3cf1 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -987,7 +987,7 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi) if (!msm_host->dsc) wc = hdisplay * dsi_get_bpp(msm_host->format) / 8 + 1; else - wc = mode->hdisplay / 2 + 1; + wc = msm_host->dsc->slice_chunk_size * msm_host->dsc->slice_count + 1;
dsi_write(msm_host, REG_DSI_CMD_MDP_STREAM0_CTRL, DSI_CMD_MDP_STREAM0_CTRL_WORD_COUNT(wc) |