X crashes on brightness change on couple of laptop models

[Scott G. Miller]

Binary package hint: xserver-xorg

When the brightness is increased with the system hotkey, X crashes within a second or two. This seems to be triggered by a power management event.

Running fglrx, but have tried multiple versions. I will try ATI soon. Attaching the stack trace from the Xorg log.

[Scott G. Miller (sgmiller)]

Attached full Xorg.0.log, including stack trace.

[Scott G. Miller (sgmiller)]

I should add, this is on Ubuntu Edgy, with Xorg 7.1.1. This bug occurs with the stock fglrx driver from Ubuntu's restricted modules, but also in the latest binary release from ATI.

[Scott G. Miller (sgmiller)]

And on a Thinkpad T60 with the Core 2 Duo 2ghz in 64-bit Ubuntu.

[Scott G. Miller (sgmiller)]

More info:

This occurs with the vesa driver as well, which is the only other one which supports my hardware. Stranger, it occurs only when *increasing* the brightness, not decreasing it.
It also occurs whether or not the ibm-acpi module is loaded.

[Scott G. Miller (sgmiller)]

Last comment for now:

The crash only occurs when the brightness is increased using the Fn-HOME combination. If I adjust the brightness in any direction via /proc/acpi/ibm/brightness, I get the correct Gnome on screen indicator and brightness change without incident. I'll try playing with xev and see if there is anything being registered as a keystroke that maybe is conflicting.

[Jochem Kossen (jkossen)]

Same problem here with an R60 and feisty fully updated. In my case it appears the 'video' kernel module conflicts with the 'ibm_acpi' module. Putting 'blacklist video' in /etc/modprobe.d/blacklist resolved the issue for me.

Problem left is that setting the brightness with the keyboard can only switch to 100% or 0% (no steps in between), but that's a different bug i think.

[Ian Redfern (ian-redfern)]

Same problem on Feisty Herd 5 with ThinkPad X60. Putting 'blacklist video' in /etc/modprobe.d/blacklist works fine and can now cycle through all 8 brightness settings using keyboard.

[Ante Karamatić (ivoks)]

I can confirm this on Toshiba Sattelite Pro U200. Until Xorg is started, changing brightness works as expected. When Xorg starts, it's like every time i change brightness, system does dpms off. If I keep pressing Fn+F6/7, eventually screen will appear again.

In my case, Xorg doesn't crash, it just puts screen 'in sleep'.

And yes, blacklisting video ACPI driver resolves this issue.

[Ante Karamatić (ivoks)]

Obviously, this is a confirmed bug. It's caused by kernel module with X started.