Comment 102 for bug 954661

David Piggott (dhpiggott) wrote :

I spoke a bit too soon it seems.

It had been working fine. Just now I left my laptop for ~5 minutes (it was on, screen open, brightness on full when I left).

I came back and found the brightness stuck on minimum (and my session had timed out, prompting me for my password - presumably something that happened as part of the time out is what triggered this bug and thus the brightness to be stuck on minimum).

Echoing 0 to /sys/class/backlight/intel_backlight/brightness did not fix it. Suspending and unsuspending the laptop did fix it - the brightness was back at full when I unsuspended, and I have control again.

I seem to recall reading either further up on here or elsewhere that the root cause is/was a race condition. I know next to nothing about things at this level (my current expertise is in Android and at the SDK level) but what I saw just now seemed like it could be explained in terms of a race condition.