Hi everyone, I have an Acer 4810TG which is affected by this bug. I have 3 OSs 
installed: Windows 7 64bit, Ubuntu 10.4 32bit and Fedora 13 64bit (KDE only), 
and the bios version is 1.35 (released April 22nd).
The new bios didn't make any difference for me, otherwise here is what i could 
observe:
-on W7, the brightness hotkeys do work, but not very accurately: i can 
apparently set 10 different levels, but the lower three have the same 
brightness, so that the last 2 keypresses when decreasing, and 2 when 
increasing it cause no effect at all; furthermore i have no OSD feedback. These 
glitches could be sign of poor support to W7 from Acer, I had Vista 
preinstalled.
- On Ubuntu with the given workaround (nomodeset apci_backlight=vendor) the 
controls work very well, ~20 levels with the nice OSD. Unfortunately this 
cannot be done in F13, which requires KMS on intel cards.
- On Ubuntu and Fedora with desktop effects disabled, and default kernel 
arguments (except "i8042.nomux", needed for a touchpad bug), thus with KMS 
enabled, i have a behavior similar to W7, but with even more inaccurate 
control: the number of levels is not fixed, and i get an OSD which, at least on 
Fedora, shows incorrect values. What's more interesting is that as soon as i 
reactivate compositing everything freezes. In Ubuntu the only way to recover 
control is to forcibly shut down the notebook, whilst in fedora i can restart 
the X server (with ctrl+alt+back) but only start new sessions without 
compositing, if i login to a user having it enabled i get stuck at the loading 
splashscreen.
An interesting fact is that ANY OPENGL ACTIVITY seems to trigger the bug, not 
only enabling desktop compositing but also starting "glxgears" for example 
causes me a system freeze, although not always immediately.

I think this bug is not in compiz, but in kernel modesetting instead!
Unluckily I currently don't have the time to do much further testing,
such as some with the Radeon discrete GPU (i got some freezes with that
to, anyway).

-- 
[gm45] Adjusting Brightness in Acer Aspire Timelines causes system freeze in 
4810T and 5810T models
https://bugs.launchpad.net/bugs/446717
You received this bug notification because you are a member of Ubuntu-X,
which is subscribed to xserver-xorg-video-intel in ubuntu.

_______________________________________________
Mailing list: https://launchpad.net/~ubuntu-x-swat
Post to     : ubuntu-x-swat@lists.launchpad.net
Unsubscribe : https://launchpad.net/~ubuntu-x-swat
More help   : https://help.launchpad.net/ListHelp

Reply via email to