Comment 21 for bug 765438

Revision history for this message
Helias Fotiadis (heliasfotiadis) wrote : Re: On startup, the backlight is off on laptop

Hi. I've been having the same problem, too since the releace of Natty and I 've been working on this on https://bugs.launchpad.net/ubuntu/+source/linux/+bug/773740. I' m using the kamal mostafa patched kernel now and when I turn on my laptop from the mains I always get no backlight on the welcoming screen and as soon as I hear the log-in sound I can tell that the desktop is now active and I use the brightness hotkeys to increase the brightness. Note that the keys work in reverse way meaning that the hotkey which should reduce the brightness now increases it. But, yesterday I noticed something strange. When I power my laptop on with its battery only I get the "Ubuntu" starting/welcoming screen with no backlight as usual but just before that screen disappears in order to be replaced by the desktop screen the bachlight is restored and I can see. And then, when I press the brightness hotkey I am surprised to see that the brightness bar is halfway full.
Note 1: The hotkeys still work in reverse way.
Note 2: This isn't happening when I use battery AND mains in order to recharge it.
Note 3: I am not using the i915.alse_backlight=1 parameter though it fixes the backlight because
a) It is pretty irritating to do this every time I turn my laptop on and
b) It somewhat messes up my screen by making it wider and that is something I don't like.
That 's all the information I can give you.
Peace.