On Wed, Jul 31, 2013 at 12:14 AM, Matthew Garrett <mjg59@xxxxxxxxxxxxx> wrote: > On Tue, Jul 30, 2013 at 07:11:06PM -0500, Felipe Contreras wrote: > >> No, the ACPI driver is exposing a backlight interface, which has a >> defined stable API. > > From the ACPI spec: > > 'The OEM may define the number 0 as "Zero brightness" that can mean to > turn off the lighting (e.g. LCD panel backlight) in the device.' > > There's no mechanism for an OS to know whether or not a firmware > implementation will actually turn the backlight off at 0, so there's no > way the OS can define the lowest backlight state as anything other than > "May or may not turn the screen off". Yes there is; quirks. -- Felipe Contreras -- 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
