On Tue, 2013-09-17 at 17:23 +0800, Aaron Lu wrote: > According to Matthew Garrett, "Windows 8 leaves backlight control up > to individual graphics drivers rather than making ACPI calls itself. > There's plenty of evidence to suggest that the Intel driver for > Windows 8 doesn't use the ACPI interface, including the fact that > it's broken on a bunch of machines when the OS claims to support > Windows 8. The simplest thing to do appears to be to disable the > ACPI backlight interface on these systems". > > So for Win8 systems, if there is native backlight control interface > registered by GPU driver, ACPI video will not register its own. For > users who prefer to keep ACPI video's backlight interface, the existing > kernel cmdline option acpi_backlight=video can be used. > > This patch is an evolution from previous work done by Matthew Garrett, > Chun-Yi Lee, Seth Forshee and Rafael J. Wysocki. > > Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> Tested-by: Igor Gnatenko <i.gnatenko.brain@xxxxxxxxx> > --- > drivers/acpi/internal.h | 5 ++--- > drivers/acpi/video.c | 27 +++++---------------------- > drivers/acpi/video_detect.c | 14 ++++++++++++-- > 3 files changed, 19 insertions(+), 27 deletions(-) -- Igor Gnatenko Fedora release 20 (Heisenbug) Linux 3.12.0-0.rc1.git0.1.fc20.x86_64 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
