This is a note to let you know that I've just added the patch titled
drm/bridge: lt8912b: fix corrupted image output
to the 5.15-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-lt8912b-fix-corrupted-image-output.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c3bcdd9bc6b138079b260c2559a5217b22174ecb
Author: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
Date: Thu Sep 22 14:43:05 2022 +0200
drm/bridge: lt8912b: fix corrupted image output
[ Upstream commit 051ad2788d35ca07aec8402542e5d38429f2426a ]
Correct I2C address for the register list in lt8912_write_lvds_config(),
these registers are on the first I2C address (0x48), the current
function is just writing garbage to the wrong registers and this creates
multiple issues (artifacts and output completely corrupted) on some HDMI
displays.
Correct I2C address comes from Lontium documentation and it is the one
used on other out-of-tree LT8912B drivers [1].
[1] https://github.com/boundarydevices/linux/blob/boundary-imx_5.10.x_2.0.0/drivers/video/lt8912.c#L296
Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge")
Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
Signed-off-by: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>
Acked-by: Adrien Grassein <adrien.grassein@xxxxxxxxx>
Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-4-dev@xxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c
index 6e04d51b4636..82169b6bfca1 100644
--- a/drivers/gpu/drm/bridge/lontium-lt8912b.c
+++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c
@@ -186,7 +186,7 @@ static int lt8912_write_lvds_config(struct lt8912 *lt)
{0x03, 0xff},
};
- return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
+ return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
};
static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b)
