This is a note to let you know that I've just added the patch titled drm/amd/display: Report to ACPI video if no panels were found to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-amd-display-report-to-acpi-video-if-no-panels-we.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 12bb6676eb59e215076fa8072b5bbef98fa55deb Author: Mario Limonciello <mario.limonciello@xxxxxxx> Date: Thu Dec 8 10:42:06 2022 -0600 drm/amd/display: Report to ACPI video if no panels were found [ Upstream commit c573e240609ff781a0246c0c8c8351abd0475287 ] On desktop APUs amdgpu doesn't create a native backlight device as no eDP panels are found. However if the BIOS has reported backlight control methods in the ACPI tables then an acpi_video0 backlight device will be made 8 seconds after boot. This has manifested in a power slider on a number of desktop APUs ranging from Ryzen 5000 through Ryzen 7000 on various motherboard manufacturers. To avoid this, report to the acpi video detection that the system does not have any panel connected in the native driver. Link: https://bugzilla.redhat.com/show_bug.cgi?id=1783786 Reported-by: Hans de Goede <hdegoede@xxxxxxxxxx> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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 c2c26fbea512..6f1cc5ce4c7a 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4372,6 +4372,10 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev) amdgpu_set_panel_orientation(&aconnector->base); } + /* If we didn't find a panel, notify the acpi video detection */ + if (dm->adev->flags & AMD_IS_APU && dm->num_of_edps == 0) + acpi_video_report_nolcd(); + /* Software is initialized. Now we can register interrupt handlers. */ switch (adev->asic_type) { #if defined(CONFIG_DRM_AMD_DC_SI)