> From: "Ted Unangst" <[email protected]> > Date: Wed, 09 Dec 2015 08:22:09 -0500 > > Ted Unangst wrote:
> > Thinkpad X1 2015 (broadwell). This is a recent regression, though > > I'm not sure when it was introduced. I have lidsuspend=0. When I > > close the lid and open it again, the screen comes back at 100% > > brightness. As in, far too bright. > > > > Previously, the screen would always open back up at the same > > brightness level I closed it at. kettenis mentioned that the > > keyboard brightness keys work (they do) but that's a recent > > addition. For many months, they did not. I wonder if the changes > > are correlated. > > Little more info. Sorry, it's not related to lid closing. It's related to > power status changing. (which tends to happen in correlation with lid > operations). > > Every time I attach or remove the power plug the screen jumps to 100% > brightness. This would almost even make sense if it only happened when > plugging in, but in what world do I want the screen to jump from 20% to 100% > when I *remove* power? Ah, that makes more sense. This exact same thing happens on older Thinkpads as well. At least my x220 behaves exactly the same way. I think what happens here is that it resets the screen brightness to the BIOS-defined default levels on these events. They just happen to be both set to 100%. On older machines I think you could define these in the BIOS setup. There probably is a propriatary Windows App to set them on modern Thinkpads. Perhaps some code could be added to acpithinkpad(4) to make this behave in a better way. My comments (and suggestion) about the erratic behaviour of the brightness keys still applies though.
