The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
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 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
[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_...
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
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 c911b30de658..c27cb47bc988 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4242,7 +4242,8 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev) } 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); }