From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Roman Li <Roman.Li@amd.com>,
        =?UTF-8?q?Samuel=20=C4=8Cavoj?= <samuel@cavoj.net>,
        Alex Deucher <alexander.deucher@amd.com>,
        Jasdeep Dhillon <Jasdeep.Dhillon@amd.com>
Subject: [PATCH 5.15 062/179] drm/amd/display: Fix OLED brightness control on eDP
Date:   Mon, 29 Nov 2021 19:17:36 +0100
Message-Id: <20211129181721.002093923@linuxfoundation.org>
In-Reply-To: <20211129181718.913038547@linuxfoundation.org>
References: <20211129181718.913038547@linuxfoundation.org>
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From: Roman Li <Roman.Li@amd.com>

commit dab60582685aabdae2d4ff7ce716456bd0dc7a0f upstream.

[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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3846,6 +3846,9 @@ 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 (amdgpu_dc_feature_mask & DC_PSR_MASK)
 				amdgpu_dm_set_psr_caps(link);
 		}