drivers/gpu/drm/msm/dp/dp_ctrl.c | 2 ++ 1 file changed, 2 insertions(+)
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")
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
---
drivers/gpu/drm/msm/dp/dp_ctrl.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index cdfcb54a3618..c7a89ab21e09 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1286,6 +1286,8 @@ 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))
--
2.44.0
Quoting Abhinav Kumar (2024-07-25 15:04:50) > 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") > Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com> > --- Reviewed-by: Stephen Boyd <swboyd@chromium.org>
On Fri, 26 Jul 2024 at 01:05, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote: > > 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") > Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Tested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> # SM8350-HDK -- With best wishes Dmitry
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