On Fri 2019-06-28 08:55:16, Daniel Thompson wrote: > On Wed, Jun 26, 2019 at 04:56:18PM +0200, Pavel Machek wrote: > > On Mon 2019-06-24 13:31:13, Matthias Kaehlcke wrote: > > > Check if a brightness curve specified in the device tree is linear or > > > not and set the corresponding property accordingly. This makes the > > > scale type available to userspace via the 'scale' sysfs attribute. > > > > > > To determine if a curve is linear it is compared to a interpolated linear > > > curve between min and max brightness. The curve is considered linear if > > > no value deviates more than +/-5% of ${brightness_range} from their > > > interpolated value. > > > > I don't think this works. Some hardware does takes brightness in perceptual units, > > converting it in the LED controller. > > This check is exclusive to PWM backlights so I'd like to double check > that you are thinking specifically of hardware that takes it's signal > from the PWM and works in perceptual units? I missed that details. Taking PWM input then converting it to perceptual units would indeed be strange. Sorry, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html