drm/amd/display: Do not send training pattern if VS Different

[Why]
The DP 1.4a Spec requires that training pattern only under certain
specific conditions. Currently driver will re-send
training pattern every time voltage swing value changes,
but that should not be the case.

[How]
Do not re-send training pattern every time VS values
are different. Only send it on the first iteration.

Signed-off-by: Sung Lee <sung.lee@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Abdoulaye Berthe <Abdoulaye.Berthe@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Sung Lee 2020-01-03 14:03:52 -05:00 committed by Alex Deucher
parent 43563bc2e6
commit 50d2c6027e

View file

@ -983,7 +983,7 @@ static enum link_training_result perform_clock_recovery_sequence(
offset);
/* 2. update DPCD of the receiver*/
if (!retries_cr)
if (!retry_count)
/* EPR #361076 - write as a 5-byte burst,
* but only for the 1-st iteration.*/
dpcd_set_lt_pattern_and_lane_settings(