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-   -   Spurious events from Cap Sensor Buttons on Lenovo Z580 (http://www.linuxquestions.org/questions/linux-laptop-and-netbook-25/spurious-events-from-cap-sensor-buttons-on-lenovo-z580-4175436948/)

XMBC 11-13-2012 09:52 AM

Spurious events from Cap Sensor Buttons on Lenovo Z580
 
Hi everyone,

I am running Debian Wheezy, Kernel 3.2.0-4-amd64 with Xfce on a recently bought Lenovo Z580. I am having problems with spurious events from the Cap Sensor Buttons (extra buttons that control, e.g., the volume).
They are extremely annoying since they stop the monitor from switching off when the laptop is idle (and when I switch it off manually via 'xset dpms force off' it will switch back next time such an event occurs).

The events occur every 20 seconds or so if and only if the laptop is running on battery power. When the AC adapter is plugged in everything is fine.
xev reports the events as follows (keycode 248 is what makes me think that it is indeed the cap sensor buttons that are to blame):

Code:

KeyPress event, serial 40, synthetic NO, window 0x4000001,
    root 0xaf, subw 0x0, time 658898, (320,112), root:(1081,385),
    state 0x10, keycode 248 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 40, synthetic NO, window 0x4000001,
    root 0xaf, subw 0x0, time 658898, (320,112), root:(1081,385),
    state 0x10, keycode 248 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False


Is there anything I can do about this such as
- stop the events from occuring or
- somehow tell the OS that events with keycode 248 should be disregarded when determining whether the laptop is idle
- if nothing else helps, switch the buttons off (I thought this might be possible in the BIOS, but I could not find anything there)?

Thanks in advance.

business_kid 11-18-2012 03:53 AM

Every 20 seconds is bad. Report bugs, and save some other poor dweeb the same issue.

Cap sensor - capacitive? clean them - might help. You can use an .Xmodmap file in X to map it to null or the like. There probably is one.

business_kid 11-19-2012 06:15 AM

Afterthought here.

I had something like this from a m/b with Via chipset back around kernel 2.6.18. It logged incessant overcurrent changes, and was a known issue, but never traced. It was solved by modifying the ehci_hcd code to output register values to log as well.

Then it could be seen that the hardware was ignoring the registers supposed to control it. So an option was added
option ehci_hcd ignore_oc=1 (inserted into 2.6.19)

and that stopped it. Nothing was logged. If this is a hardware issue, you may need something similar.


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