ACPI: video: Add new hw_changes_brightness quirk, set it on PB Easynote MZ35
authorHans de Goede <hdegoede@redhat.com>
Fri, 12 Jul 2019 10:00:33 +0000 (12:00 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tue, 16 Jul 2019 15:30:09 +0000 (17:30 +0200)
commit4f7f96453b462b3de0fa18d18fe983960bb5ee7f
tree413fc3dfbf5f5a0a16336543ce55b762eabf1172
parenta131c2bf165684315f606fdd88cf80be22ba32f3
ACPI: video: Add new hw_changes_brightness quirk, set it on PB Easynote MZ35

Some machines change the brightness themselves when a brightness hotkey
gets pressed, despite us telling them not to. This causes the brightness to
go two steps up / down when the hotkey is pressed. This is esp. a problem
on older machines with only a few brightness levels.

This commit adds a new hw_changes_brightness quirk which makes
acpi_video_device_notify() only call backlight_force_update(...,
BACKLIGHT_UPDATE_HOTKEY) and not do anything else, notifying userspace
that the brightness was changed and leaving it at that fixing the dual
step problem.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204077
Reported-by: Kacper Piwiński <cosiekvfj@o2.pl>
Tested-by: Kacper Piwiński <cosiekvfj@o2.pl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/acpi/acpi_video.c