diff options
author | Hans de Goede <hdegoede@redhat.com> | 2022-05-16 16:04:17 +0200 |
---|---|---|
committer | Hans de Goede <hdegoede@redhat.com> | 2022-09-03 12:17:26 +0200 |
commit | 5e0e33f92ea5d891ea37fbc5119031024c154805 (patch) | |
tree | 98b5355b931cb69a06420773263bee1b2563342e /drivers/platform/x86/nvidia-wmi-ec-backlight.c | |
parent | c0f50c5de93b8afb2281009a33c124e82973e457 (diff) | |
download | linux-stable-5e0e33f92ea5d891ea37fbc5119031024c154805.tar.gz linux-stable-5e0e33f92ea5d891ea37fbc5119031024c154805.tar.bz2 linux-stable-5e0e33f92ea5d891ea37fbc5119031024c154805.zip |
drm/radeon: Register ACPI video backlight when skipping radeon backlight registration
Typically the acpi_video driver will initialize before radeon, which
used to cause /sys/class/backlight/acpi_video0 to get registered and then
radeon would register its own radeon_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 radeon skips
registering its own backlight device because of e.g. 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 radeon drm_device gets registered with userspace.
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Diffstat (limited to 'drivers/platform/x86/nvidia-wmi-ec-backlight.c')
0 files changed, 0 insertions, 0 deletions