This is a note to let you know that I've just added the patch titled
drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer
to the 6.5-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-bridge-samsung-dsim-drain-command-transfer-fifo-.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f596948fa4c365dcd5ac905f960bfeb06b537f62
Author: Marek Vasut <marex@xxxxxxx>
Date: Thu Jun 15 22:15:11 2023 +0200
drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer
[ Upstream commit 14806c6415820b1c4bc317655c40784d050a2edb ]
Wait until the command transfer FIFO is empty before loading in the next
command. The previous behavior where the code waited until command transfer
FIFO was not full suffered from transfer corruption, where the last command
in the FIFO could be overwritten in case the FIFO indicates not full, but
also does not have enough space to store another transfer yet.
Signed-off-by: Marek Vasut <marex@xxxxxxx>
Reviewed-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
Tested-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx> # imx8mm-icore
Link: https://patchwork.freedesktop.org/patch/msgid/20230615201511.565923-1-marex@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 73ec60757dbcb..9e253af69c7a1 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1009,7 +1009,7 @@ static int samsung_dsim_wait_for_hdr_fifo(struct samsung_dsim *dsi)
do {
u32 reg = samsung_dsim_read(dsi, DSIM_FIFOCTRL_REG);
- if (!(reg & DSIM_SFR_HEADER_FULL))
+ if (reg & DSIM_SFR_HEADER_EMPTY)
return 0;
if (!cond_resched())
