On 12/8/22 11:42, Mario Limonciello wrote: > 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> Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> Harry > --- > 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)
