@@ -748,10 +748,10 @@ static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native)
return acpi_backlight_video;
/* Use native if available */
- if (native_available && prefer_native_over_acpi_video())
+ if (native_available)
return acpi_backlight_native;
- /* No ACPI video (old hw), use vendor specific fw methods. */
+ /* No ACPI video/native (old hw), use vendor specific fw methods. */
return acpi_backlight_vendor;
}
@@ -763,18 +763,6 @@ EXPORT_SYMBOL(acpi_video_get_backlight_type);
bool acpi_video_backlight_use_native(void)
{
- /*
- * Call __acpi_video_get_backlight_type() to let it know that
- * a native backlight is available.
- */
- __acpi_video_get_backlight_type(true);
-
- /*
- * For now just always return true. There is a whole bunch of laptop
- * models where (video_caps & ACPI_VIDEO_BACKLIGHT) is false causing
- * __acpi_video_get_backlight_type() to return vendor, while these
- * models only have a native backlight control.
- */
- return true;
+ return __acpi_video_get_backlight_type(true) == acpi_backlight_native;
}
EXPORT_SYMBOL(acpi_video_backlight_use_native);
When available prefer native backlight control over vendor backlight control. Testing has shown that there are quite a few laptop models which rely on native backlight control (they don't have ACPI video bus backlight control) and on which acpi_osi_is_win8() returns false. Currently __acpi_video_get_backlight_type() returns vendor on these laptops, leading to an empty /sys/class/backlight. As a workaround for this acpi_video_backlight_use_native() has been temporarily changed to always return true. This re-introduces the problem of having multiple backlight devices under /sys/class/backlight for a single panel. Change __acpi_video_get_backlight_type() to prefer native over vendor when available. So that it returns native on these models. And change acpi_video_backlight_use_native() back to only return true when __acpi_video_get_backlight_type() returns native. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/acpi/video_detect.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-)