This is a note to let you know that I've just added the patch titled
drm/msm/dp: reset the link phy params before link training
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-msm-dp-reset-the-link-phy-params-before-link-tra.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 b039b3ed5ebc705be4aea874e09dfe769f45215e
Author: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Date: Thu Jul 25 15:04:50 2024 -0700
drm/msm/dp: reset the link phy params before link training
[ Upstream commit 319aca883bfa1b85ee08411541b51b9a934ac858 ]
Before re-starting link training reset the link phy params namely
the pre-emphasis and voltage swing levels otherwise the next
link training begins at the previously cached levels which can result
in link training failures.
Fixes: 8ede2ecc3e5e ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Tested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> # SM8350-HDK
Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Patchwork: https://patchwork.freedesktop.org/patch/605946/
Link: https://lore.kernel.org/r/20240725220450.131245-1-quic_abhinavk@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 bd1343602f553..3c001b792423b 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1248,6 +1248,8 @@ static int dp_ctrl_link_train(struct dp_ctrl_private *ctrl,
link_info.rate = ctrl->link->link_params.rate;
link_info.capabilities = DP_LINK_CAP_ENHANCED_FRAMING;
+ dp_link_reset_phy_params_vx_px(ctrl->link);
+
dp_aux_link_configure(ctrl->aux, &link_info);
if (drm_dp_max_downspread(dpcd))
