diff options
| author | Hans de Goede <hdegoede@redhat.com> | 2022-05-16 11:32:33 +0200 |
|---|---|---|
| committer | Hans de Goede <hdegoede@redhat.com> | 2022-09-03 12:17:26 +0200 |
| commit | c0f50c5de93b8afb2281009a33c124e82973e457 (patch) | |
| tree | b3746315e19f25c50399de24416fd7f71352dd4e | |
| parent | c053383813fd17296db99cea78e058ed4d53019c (diff) | |
drm/amdgpu: Register ACPI video backlight when skipping amdgpu backlight registration
Typically the acpi_video driver will initialize before amdgpu, which
used to cause /sys/class/backlight/acpi_video0 to get registered and then
amdgpu would register its own amdgpu_bl# device later. After which
the drivers/acpi/video_detect.c code unregistered the acpi_video0 device
to avoid there being 2 backlight devices.
This means that userspace used to briefly see 2 devices and the
disappearing of acpi_video0 after a brief time confuses the systemd
backlight level save/restore code, see e.g.:
https://bbs.archlinux.org/viewtopic.php?id=269920
To fix this the ACPI video code has been modified to make backlight class
device registration a separate step, relying on the drm/kms driver to
ask for the acpi_video backlight registration after it is done setting up
its native backlight device.
Add a call to the new acpi_video_register_backlight() when amdgpu skips
registering its own backlight device because of either the firmware_flags
or the acpi_video_get_backlight_type() return value. This ensures that
if the acpi_video backlight device should be used, it will be available
before the amdgpu drm_device gets registered with userspace.
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/atombios_encoders.c | 9 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 |
2 files changed, 9 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c index b4e3cedceaf8..6be9ac2b9c5b 100644 --- a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c +++ b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c @@ -184,11 +184,11 @@ void amdgpu_atombios_encoder_init_backlight(struct amdgpu_encoder *amdgpu_encode return; if (!(adev->mode_info.firmware_flags & ATOM_BIOS_INFO_BL_CONTROLLED_BY_GPU)) - return; + goto register_acpi_backlight; if (!acpi_video_backlight_use_native()) { drm_info(dev, "Skipping amdgpu atom DIG backlight registration\n"); - return; + goto register_acpi_backlight; } pdata = kmalloc(sizeof(struct amdgpu_backlight_privdata), GFP_KERNEL); @@ -225,6 +225,11 @@ void amdgpu_atombios_encoder_init_backlight(struct amdgpu_encoder *amdgpu_encode error: kfree(pdata); return; + +register_acpi_backlight: + /* Try registering an ACPI video backlight device instead. */ + acpi_video_register_backlight(); + return; } void 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 a64baff041a7..3f456978dca7 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4059,6 +4059,8 @@ amdgpu_dm_register_backlight_device(struct amdgpu_display_manager *dm) if (!acpi_video_backlight_use_native()) { drm_info(adev_to_drm(dm->adev), "Skipping amdgpu DM backlight registration\n"); + /* Try registering an ACPI video backlight device instead. */ + acpi_video_register_backlight(); return; } |