From f9cd790d6f25764c8cf5f36769e28d26fde17b2c Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 16 Feb 2021 12:22:40 -0500
Subject: [PATCH] drm/amdgpu/display: restore AUX_DPHY_TX_CONTROL for DCN2.x

Commit 098214999c8f added fetching of the AUX_DPHY register
values from the vbios, but it also changed the default values
in the case when there are no values in the vbios.  This causes
problems with displays with high refresh rates.  To fix this,
switch back to the original default value for AUX_DPHY_TX_CONTROL.

Fixes: 098214999c8f ("drm/amd/display: Read VBIOS Golden Settings Tbl")
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1426
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Igor Kravchenko <Igor.Kravchenko@amd.com>
Cc: Aric Cyr <Aric.Cyr@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
---
 drivers/gpu/drm/amd/display/dc/dcn20/dcn20_link_encoder.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_link_encoder.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_link_encoder.c
index fa013496e26ba..2f9bfaeaba8d6 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_link_encoder.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_link_encoder.c
@@ -341,8 +341,7 @@ void enc2_hw_init(struct link_encoder *enc)
 	} else {
 		AUX_REG_WRITE(AUX_DPHY_RX_CONTROL0, 0x103d1110);
 
-		AUX_REG_WRITE(AUX_DPHY_TX_CONTROL, 0x21c4d);
-
+		AUX_REG_WRITE(AUX_DPHY_TX_CONTROL, 0x21c7a);
 	}
 
 	//AUX_DPHY_TX_REF_CONTROL'AUX_TX_REF_DIV HW default is 0x32;
-- 
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