From ae7453559e0d87779e227c6a24af1a67a28a81f3 Mon Sep 17 00:00:00 2001
From: hersen wu <hersenxs.wu@amd.com>
Date: Mon, 22 Jun 2020 13:29:16 -0400
Subject: drm/amd/display: OLED panel backlight adjust not work with external
Git-commit: b448d30b0c303d5454ea572b772d1ffae96bc6e7
Patch-mainline: v5.8-rc6
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
 display connected

[Why]
amdgpu_dm->backlight_caps is for single eDP only. the caps are upddated
for very connector. Real eDP caps will be overwritten by other external
display. For OLED panel, caps->aux_support is set to 1 for OLED pnael.
after external connected, caps+.aux_support is set to 0. This causes
OLED backlight adjustment not work.

[How]
within update_conector_ext_caps, backlight caps will be updated only for
eDP connector.

Cc: stable@vger.kernel.org
Signed-off-by: hersen wu <hersenxs.wu@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index b30e31444aef..86ffa0c2880f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2019,6 +2019,7 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
 	struct amdgpu_display_manager *dm;
 	struct drm_connector *conn_base;
 	struct amdgpu_device *adev;
+	struct dc_link *link = NULL;
 	static const u8 pre_computed_values[] = {
 		50, 51, 52, 53, 55, 56, 57, 58, 59, 61, 62, 63, 65, 66, 68, 69,
 		71, 72, 74, 75, 77, 79, 81, 82, 84, 86, 88, 90, 92, 94, 96, 98};
@@ -2026,6 +2027,10 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
 	if (!aconnector || !aconnector->dc_link)
 		return;
 
+	link = aconnector->dc_link;
+	if (link->connector_signal != SIGNAL_TYPE_EDP)
+		return;
+
 	conn_base = &aconnector->base;
 	adev = conn_base->dev->dev_private;
 	dm = &adev->dm;
-- 
2.28.0