This is a note to let you know that I've just added the patch titled
drm/msm/dp: stop link training after link training 2 failed
to the 5.17-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-msm-dp-stop-link-training-after-link-training-2-.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0dd877546b83dc9e2e3074c5f421148a9c0705f3
Author: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Date: Tue Jan 18 10:47:28 2022 -0800
drm/msm/dp: stop link training after link training 2 failed
[ Upstream commit 9051d629dbf7a998a40f7eac65a9512b01bc3bb8 ]
Each DP link training contains link training 1 followed by link
training 2. There is maximum of 5 retries of DP link training
before declared link training failed. It is required to stop link
training at end of link training 2 if it is failed so that next
link training 1 can start freshly. This patch fixes link compliance
test case 4.3.1.13 (Source Device Link Training EQ Fallback Test).
Changes in v10:
-- group into one series
Changes in v11:
-- drop drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read
Fixes: 2e0adc765d88 ("drm/msm/dp: do not end dp link training until video is ready")
Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1642531648-8448-5-git-send-email-quic_khsieh@xxxxxxxxxxx
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 9c80b493f974..8d1ea694d06c 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1748,6 +1748,9 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
/* end with failure */
break; /* lane == 1 already */
}
+
+ /* stop link training before start re training */
+ dp_ctrl_clear_training_pattern(ctrl);
}
}
