This is a note to let you know that I've just added the patch titled
soc: mediatek: mt8192-mmsys: Fix dither to dsi0 path's input sel
to the 5.16-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:
soc-mediatek-mt8192-mmsys-fix-dither-to-dsi0-path-s-.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3a9f673df7cc65b348b841639dc89104e284c177
Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Date: Fri Jan 28 15:20:56 2022 +0100
soc: mediatek: mt8192-mmsys: Fix dither to dsi0 path's input sel
[ Upstream commit c432cd598a185afefba1ac3b0ee226f222f71341 ]
In commit d687e056a18f ("soc: mediatek: mmsys: Add mt8192 mmsys routing table"),
the mmsys routing table for mt8192 was introduced but the input selector
for DITHER->DSI0 has no value assigned to it.
This means that we are clearing bit 0 instead of setting it, blocking
communication between these two blocks; due to that, any display that
is connected to DSI0 will not work, as no data will go through.
The effect of that issue is that, during bootup, the DRM will block for
some time, while atomically waiting for a vblank that never happens;
later, the situation doesn't get better, leaving the display in a
non-functional state.
To fix this issue, fix the route entry in the table by assigning the
dither input selector to MT8192_DISP_DSI0_SEL_IN.
Fixes: d687e056a18f ("soc: mediatek: mmsys: Add mt8192 mmsys routing table")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Tested-by: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220128142056.359900-1-angelogioacchino.delregno@xxxxxxxxxxxxx
Signed-off-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/soc/mediatek/mt8192-mmsys.h b/drivers/soc/mediatek/mt8192-mmsys.h
index 6f0a57044a7b..6aae0b12b6ff 100644
--- a/drivers/soc/mediatek/mt8192-mmsys.h
+++ b/drivers/soc/mediatek/mt8192-mmsys.h
@@ -53,7 +53,8 @@ static const struct mtk_mmsys_routes mmsys_mt8192_routing_table[] = {
MT8192_AAL0_SEL_IN_CCORR0
}, {
DDP_COMPONENT_DITHER, DDP_COMPONENT_DSI0,
- MT8192_DISP_DSI0_SEL_IN, MT8192_DSI0_SEL_IN_DITHER0
+ MT8192_DISP_DSI0_SEL_IN, MT8192_DSI0_SEL_IN_DITHER0,
+ MT8192_DSI0_SEL_IN_DITHER0
}, {
DDP_COMPONENT_RDMA0, DDP_COMPONENT_COLOR0,
MT8192_DISP_RDMA0_SOUT_SEL, MT8192_RDMA0_SOUT_COLOR0,
