From dab60582685aabdae2d4ff7ce716456bd0dc7a0f Mon Sep 17 00:00:00 2001
From: Roman Li <Roman.Li@amd.com>
Date: Wed, 17 Nov 2021 10:05:36 -0500
Subject: [PATCH] drm/amd/display: Fix OLED brightness control on eDP
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Git-commit: dab60582685aabdae2d4ff7ce716456bd0dc7a0f
Alt-commit: b295ce39912cb10d3bd34fba556e4009b67954db
Patch-mainline: v5.16-rc2
References: git-fixes

[Why]
After commit ("drm/amdgpu/display: add support for multiple backlights")
number of eDPs is defined while registering backlight device.
However the panel's extended caps get updated once before register call.
That leads to regression with extended caps like oled brightness control.

[How]
Update connector ext caps after register_backlight_device

Fixes: 7fd13baeb7a3a4 ("drm/amdgpu/display: add support for multiple backlights")
Link: https://www.reddit.com/r/AMDLaptops/comments/qst0fm/after_updating_to_linux_515_my_brightness/

Signed-off-by: Roman Li <Roman.Li@amd.com>
Tested-by: Samuel Čavoj <samuel@cavoj.net>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jasdeep Dhillon <Jasdeep.Dhillon@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3898,7 +3898,8 @@ static int amdgpu_dm_initialize_drm_devi
 		} else if (dc_link_detect(link, DETECT_REASON_BOOT)) {
 			amdgpu_dm_update_connector_after_detect(aconnector);
 			register_backlight_device(dm, link);
-
+			if (dm->num_of_edps)
+				update_connector_ext_caps(aconnector);
 			if (psr_feature_enabled)
 				amdgpu_dm_set_psr_caps(link);
 		}