ACPI: video: Force backlight native for some TongFang devices
authorWerner Sembach <wse@tuxedocomputers.com>
Thu, 7 Jul 2022 18:09:52 +0000 (20:09 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 11 Aug 2022 11:07:50 +0000 (13:07 +0200)
commit3a5fab5c45056a8d8c33880b113ae40cf23500e8
tree637b8af93b1046e01abcfa7422c0087bf45759d1
parent9894717519cc144827bf8a46b543363533e8c0fe
ACPI: video: Force backlight native for some TongFang devices

commit c752089f7cf5b5800c6ace4cdd1a8351ee78a598 upstream.

The TongFang PF5PU1G, PF4NU1F, PF5NU1G, and PF5LUXG/TUXEDO BA15 Gen10,
Pulse 14/15 Gen1, and Pulse 15 Gen2 have the same problem as the Clevo
NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2:
They have a working native and video interface. However the default
detection mechanism first registers the video interface before
unregistering it again and switching to the native interface during boot.
This results in a dangling SBIOS request for backlight change for some
reason, causing the backlight to switch to ~2% once per boot on the first
power cord connect or disconnect event. Setting the native interface
explicitly circumvents this buggy behaviour by avoiding the unregistering
process.

Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
Cc: All applicable <stable@vger.kernel.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/acpi/video_detect.c