From: Hans de Goede hdegoede@redhat.com
[ Upstream commit 9dcb34234b8235144c96103266317da33321077e ]
The HP EliteBook 8460p predates Windows 8, so it defaults to using acpi_video# for backlight control.
Starting with the 6.1.y kernels the native radeon_bl0 backlight is hidden in this case instead of relying on userspace preferring acpi_video# over native backlight devices.
It turns out that for the acpi_video# interface to work on the HP EliteBook 8460p, the brightness needs to be set at least once through the native interface, which now no longer is done breaking backlight control.
The native interface however always works without problems, so add a quirk to use native backlight on the EliteBook 8460p to fix this.
Fixes: fb1836c91317 ("ACPI: video: Prefer native over vendor") Link: https://bugzilla.redhat.com/show_bug.cgi?id=2161428 Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/video_detect.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index c20fc7ddca2f..4719978b8aa3 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -608,6 +608,14 @@ static const struct dmi_system_id video_detect_dmi_table[] = { DMI_MATCH(DMI_PRODUCT_NAME, "UX303UB"), }, }, + { + .callback = video_detect_force_native, + /* HP EliteBook 8460p */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), + DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8460p"), + }, + }, { .callback = video_detect_force_native, /* HP Pavilion g6-1d80nr / B4U19UA */