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@quicinc.com Reviewed-by: Stephen Boyd swboyd@chromium.org --- drivers/gpu/drm/msm/dp/dp_ctrl.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c index f98df93..245e1b9 100644 --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c @@ -1755,6 +1755,9 @@ 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); } }