| Message ID | 20221213232207.113607-5-marijn.suijten@somainline.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/msm: DSC Electric Boogaloo for sm8[12]50 | expand |
On 14/12/2022 01:22, Marijn Suijten wrote: > 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> > --- > drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
On 12/13/2022 3:22 PM, Marijn Suijten wrote: > 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: Abhinav Kumar <quic_abhinavk@quicinc.com> > --- > 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 b83cf70b1adb..0686c35a6fd4 100644 > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c > @@ -989,7 +989,7 @@ 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) |
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index b83cf70b1adb..0686c35a6fd4 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -989,7 +989,7 @@ 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) |
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> --- drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)