From: Wenjing Liu <Wenjing.Liu@amd.com>
Date: Wed, 23 Aug 2017 21:02:34 +0000 (-0400)
Subject: drm/amd/display: do not reset lane count in EQ fallback
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1cf49dea28dfc76f0816a4bc73c2ab975c72f55d;p=linux.git

drm/amd/display: do not reset lane count in EQ fallback

[Description]
According to DP1.4 specs we should not reset lane count back
when falling back in failing EQ training.
This causes PHY test pattern compliance to fail as infinite LT
when LT fails EQ to 4 RBR and fails CR in a loop.

Signed-off-by: Wenjing Liu <Wenjing.Liu@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

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 e19447d526ea3..446e2933474cf 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
@@ -1302,8 +1302,6 @@ bool decide_fallback_link_setting(
 					current_link_setting->lane_count);
 		} else if (!reached_minimum_link_rate
 				(current_link_setting->link_rate)) {
-			current_link_setting->lane_count =
-				initial_link_settings.lane_count;
 			current_link_setting->link_rate =
 				reduce_link_rate(
 					current_link_setting->link_rate);