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otoomet 01-29-2013 08:50 AM

keyboard sends Power Down signal
Hi gurus,

I have a HP elite 8200 desktop in dual seat setup (i5 processor, 8G ram, 2x Radeon HD6450 graphics using 'radeon' driver). It runs ubuntu 12.04 64bit and uses udev for selecting input devices for each seat. It mostly works fine, although occasionally X crashes and refuses to start during boot (another restart usually helps).

However, occasionally (about once a month) when keyboard of the seat 1 is under active use, the computer shuts down. The only somewhat relevant stuff from the logs was in X log for seat 1 (Xorg.1.log.old):


[1727096.965] (II) XKB: reuse xkmfile /var/lib/xkb/server-9D162EA1B376467B416CA78A93335F1F745AD174.xkm
[1728305.102] (II) XKB: reuse xkmfile /var/lib/xkb/server-3E90985BC446F3A94AC39BAC9D64837FE8F3A877.xkm
[1732168.896] (II) evdev: Power Button: Close
[1732168.896] (II) UnloadModule: "evdev"
[1732168.896] (II) Unloading evdev
[1732168.936] (II) evdev: Power Button: Close
[1732168.936] (II) UnloadModule: "evdev"
[1732168.936] (II) Unloading evdev
[1732168.980] (II) evdev: UVC Camera (046d:09a1): Close
[1732168.980] (II) UnloadModule: "evdev"
[1732168.980] (II) Unloading evdev
[1732169.012] (II) evdev: CHICONY HP Basic USB Keyboard: Close
[1732169.012] (II) UnloadModule: "evdev"
[1732169.012] (II) Unloading evdev
[1732169.064] (II) evdev: Logitech USB-PS/2 Optical Mouse: Close
[1732169.064] (II) UnloadModule: "evdev"
[1732169.064] (II) Unloading evdev
[1732169.128] (II) evdev: HP WMI hotkeys: Close
[1732169.128] (II) UnloadModule: "evdev"
[1732169.128] (II) Unloading evdev
[1732169.128]  ddxSigGiveUp: Closing log
[1732169.128] Server terminated successfully (0). Closing log file.

(the two first lines are probably not related).

Any ideas? Myself, I suspect it is some kind of misunderstanding between BIOS and the graphics cards, which occasionally overspills in this way. However, perhaps it can also be a faulty keyboard?

Is it possible to disable shutdown through "evdev" driver?

smallpond 01-29-2013 04:05 PM

Did somebody type 'Ctrl - Alt - Backspace', maybe? That's the hotkey to shut down X.

otoomet 01-29-2013 07:29 PM

Extremely unlikely. First, the users have mentioned only DEL, not any more complex combinations (but sometimes they do not conot confirm even that). Second, CTR-ALT-BS does not do anything under normal operation (neither does CTL-ALT-DEL). Third, computer will be shut down, not just X restarted.

The keyboard does not have any power down button. I guess it is possible to tweak the driver a bit?

otoomet 01-30-2013 05:29 PM

I have figured out that in all cases, the users can tell me, the crash has happened when pressing DEL key. By far the most cases, DEL works as expected.

Could it be SysRq spillover?

otoomet 05-15-2013 06:35 AM

after a long testing period it seems the issue was as follows:
a) the keyboard was broken, occasionally sending ctrl-alt-del instead of del.
b) ctrl-alt-del was not disabled.
I replaced the keyboard, and disabled ctr-alt-del, and haven't experienced any problems ever since :-)

(I also updated the kernel).

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