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> --- v2->v3: * Add Hans' R-b v1->v2: * No changes --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++++ 1 file changed, 4 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 512c32327eb1..b73f61ac5dd5 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4371,6 +4371,10 @@ 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) -- 2.34.1
