This is a note to let you know that I've just added the patch titled
drm/msm/dp: delete DP_RECOVERED_CLOCK_OUT_EN to fix tps4
to the 5.19-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-delete-dp_recovered_clock_out_en-to-fix-t.patch
and it can be found in the queue-5.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0d393f579bf6986ee27cb815bc7ca082f4492309
Author: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Date: Thu Aug 11 15:57:50 2022 -0700
drm/msm/dp: delete DP_RECOVERED_CLOCK_OUT_EN to fix tps4
[ Upstream commit 032d57960176ac01cc5adff5bcc5eb51317f8781 ]
Data Symbols scrambled is required for tps4 at link training 2.
Therefore SCRAMBLING_DISABLE bit should not be set for tps4 to
work.
RECOVERED_CLOCK_OUT_EN is for enable simple EYE test for jitter
measurement with minimal equipment for embedded applications purpose
and is not required to be set during normal operation. Current
implementation always have RECOVERED_CLOCK_OUT_EN bit set which
cause SCRAMBLING_DISABLE bit wrongly set at tps4 which prevent
tps4 from working.
This patch delete setting RECOVERED_CLOCK_OUT_EN to fix
SCRAMBLING_DISABLE be wrongly set at tps4.
Changes in v2:
-- fix Fixes tag
Changes in v3:
-- revise commit text
Changes in v4:
-- fix commit text newline
Changes in v5:
-- fix commit text line over 75 chars
Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Patchwork: https://patchwork.freedesktop.org/patch/497194/
Link: https://lore.kernel.org/r/1660258670-4200-1-git-send-email-quic_khsieh@xxxxxxxxxxx
Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
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 703249384e7c7..45aa06a31a9fd 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1214,7 +1214,7 @@ static int dp_ctrl_link_train_2(struct dp_ctrl_private *ctrl,
if (ret)
return ret;
- dp_ctrl_train_pattern_set(ctrl, pattern | DP_RECOVERED_CLOCK_OUT_EN);
+ dp_ctrl_train_pattern_set(ctrl, pattern);
for (tries = 0; tries <= maximum_retries; tries++) {
drm_dp_link_train_channel_eq_delay(ctrl->aux, ctrl->panel->dpcd);
