On Tue, Mar 26, 2013 at 04:13:13PM +0100, Daniel Vetter wrote: > On Tue, Mar 26, 2013 at 12:48:45PM +0100, Danny Baumann wrote: > > When controlling backlight devices via sysfs interface, user space > > generally assumes the minimum level (0) still providing a brightness > > that is usable by the user (probably due to the most commonly used > > backlight device, acpi_videoX, behaving exactly like that). This doesn't > > match the current behaviour of the intel_backlight control, though, as > > the value 0 means 'backlight off'. > > > > In order to make intel_backlight consistent to other backlight devices, > > introduce a module parameter that allows shifting the 0 level of the > > intel_backlight device. It's expressed in percentages of the maximum > > level. The default is 5, which provides a backlight level that is barely > > readable. Setting it to 0 restores the old behaviour. > > > > Signed-off-by: Danny Baumann <dannybaumann@xxxxxx> > > Thus far our assumption always was that the acpi backlight works better > than the intel native backlight. So everything only uses the intel > backlight if there's no other backlight driver by default. There are machines, such as the pnv netbook on my desk, on which intel_backlight does nothing and the only control is through acpi_backlight0. Generalising expected behaviour based on one firmware implementation is fraught with danger. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
