This is a note to let you know that I've just added the patch titled
drm/mediatek: Add return value check when reading DPCD
to the 6.1-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-mediatek-add-return-value-check-when-reading-dpc.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5d9307f355a792d450cf044cf32bafc7fcda0486
Author: Liankun Yang <liankun.yang@xxxxxxxxxxxx>
Date: Wed Dec 18 19:34:07 2024 +0800
drm/mediatek: Add return value check when reading DPCD
[ Upstream commit 522908140645865dc3e2fac70fd3b28834dfa7be ]
Check the return value of drm_dp_dpcd_readb() to confirm that
AUX communication is successful. To simplify the code, replace
drm_dp_dpcd_readb() and DP_GET_SINK_COUNT() with drm_dp_read_sink_count().
Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Liankun Yang <liankun.yang@xxxxxxxxxxxx>
Reviewed-by: Guillaume Ranquet <granquet@xxxxxxxxxxxx>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241218113448.2992-1-liankun.yang@xxxxxxxxxxxx/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index 09a496588b50..6bf50a15c9b4 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -1952,7 +1952,6 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge)
struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge);
enum drm_connector_status ret = connector_status_disconnected;
bool enabled = mtk_dp->enabled;
- u8 sink_count = 0;
if (!mtk_dp->train_info.cable_plugged_in)
return ret;
@@ -1974,8 +1973,8 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge)
* function, we just need to check the HPD connection to check
* whether we connect to a sink device.
*/
- drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count);
- if (DP_GET_SINK_COUNT(sink_count))
+
+ if (drm_dp_read_sink_count(&mtk_dp->aux) > 0)
ret = connector_status_connected;
if (!enabled) {
