From 888670711cbf702d056287471642126127e3613f Mon Sep 17 00:00:00 2001
From: Sung Lee <sung.lee@amd.com>
Date: Fri, 3 Jan 2020 14:03:52 -0500
Subject: drm/amd/display: Do not send training pattern if VS Different
Git-commit: 50d2c6027ef4d09d7c2a9d12b2a7957576c0fa3c
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
[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>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 1bd0946829e3..3bb1b481451b 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -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(
--
2.28.0