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When a key is pressed and released quickly, it will auto-repeat until the keyboard is touched again.

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It looks like the system receives the "keypress" signal alright, but the "keyrelease" seems to be lost on fast maneuvers.

The issue is easy to recreate. If I "brush" the keyboard (don't know how else to describe pressing a key for the slightest moment), then the letter appears normally, but after the prescribed delay, it will auto-repeat as if the key was kept pressed. In my case the auto-repeat delay is about half a second. This issue exists for all of the keyboard keys, including up/down arrows, backspace, etc. It does it consistently in all Ubuntu applications.

I have a Dell Precision M4800. Dual boot with Windows 8.1. The keyboard works fine in Windows.

The laptop is new. So far this is the only issue with this install. Everything else appear to be working well. I am familiar with Ubuntu 14.04 (I have it on 3 other laptops). This is the first time I've seen this issue.

I have an external USB keyboard and it doesn't have this issue. However it is so crude, and the keys so deep, that I cannot really recreate the same "brushing" effect.

All the "Universal Access" options are off.

EDIT 1: The following is from a XEV. KeyPress and KeyRelease repeats over and over:

KeyPress event, serial 37, synthetic NO, window 0x5000001,
root 0xc4, subw 0x0, time 8211573, (263,232), root:(304,284),
state 0x0, keycode 57 (keysym 0x6e, n), same_screen YES,
XLookupString gives 1 bytes: (6e) "n"
XmbLookupString gives 1 bytes: (6e) "n"
XFilterEvent returns: False

KeyRelease event, serial 37, synthetic NO, window 0x5000001,
root 0xc4, subw 0x0, time 8211591, (263,232), root:(304,284),
state 0x0, keycode 57 (keysym 0x6e, n), same_screen YES,
XLookupString gives 1 bytes: (6e) "n"
XFilterEvent returns: False

EDIT 2: Comparing two XEV sessions, one with the issue and one with a voluntary key auto-repeat, both are virtually identical except for the "KeymapNotify event".

With the issue:

KeymapNotify event, serial 29, synthetic NO, window 0x0,
keys:  4294967224 0   0   0   16  0   0   0   0   0   0   0   0   0   0   0   
       0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

Normal auto-repeat:

KeymapNotify event, serial 29, synthetic NO, window 0x0,
keys:  0   0   0   0   16  0   0   0   0   0   0   0   0   0   0   0   
       0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
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  • If you run xev, then type a key rapidly, do you see the release message: KeyRelease event, serial 33, synthetic NO, window 0x3a00001,...
    – ubfan1
    Commented Dec 31, 2014 at 5:45
  • Interesting. We can see the keypress/keyrelease being repeated forever:
    – JFRivard
    Commented Dec 31, 2014 at 6:50
  • Here's the output of the command: KeyPress event, serial 37, synthetic NO, window 0x5000001,root 0xc4, subw 0x0, time 8211552,(263,232),root:(304,284),state 0x0, keycode 57 (keysym 0x6e, n), same_screen YES,XLookupString gives 1 bytes: (6e) "n" XmbLookupString gives 1 bytes: (6e) "n" XFilterEvent returns: False KeyRelease event, serial 37, synthetic NO, window 0x5000001, root 0xc4, subw 0x0, time 8211573,(263,232),root:(304,284),state 0x0, keycode 57 (keysym 0x6e, n), same_screen YES,XLookupString gives 1 bytes: (6e) "n" XFilterEvent returns: False
    – JFRivard
    Commented Dec 31, 2014 at 6:57
  • JFRivard, please edit the output into your question, it is impossible to read in a comment.
    – Wilf
    Commented Dec 31, 2014 at 7:08
  • I still have this problem. Any help would be appreciated. Please, I am getting desperate... Thank you.
    – JFRivard
    Commented Jan 8, 2015 at 15:26

3 Answers 3

Reset to default
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Dell have now released BIOS version A13 which addresses this issue. I had the exact same problem until I updated to A13.

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  • 1
    Not too late at all Gavin. I am currently running A11. I will update to A13 right away and let you know how it goes. Thank you very much for sharing this!
    – JFRivard
    Commented Feb 9, 2015 at 0:39
  • 1
    Gavin: it worked!!! Thank you so much! You have no idea miserable this bug was making me. You saved me. Thank you thank you thank you!!!
    – JFRivard
    Commented Feb 9, 2015 at 0:55
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I experienced the same problems. Just flashed my E6440 with the latest BIOS firmware.

That seems to have fixed the issue. The release notes for the firmware explicitly mention the keyboard issue on Linux OSes should be fixed by the update.

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1
  • Thanks for sharing. So Dell Latitude E6440 laptops also have this issue. Probably other Dell models as well. The good news is that they are releasing BIOS upgrades to fix it.
    – JFRivard
    Commented Feb 24, 2015 at 14:35
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The timing indicates an auto-repeat function is being used to generate the key presses. They are much faster than you can type, and if you look at the next keypress after the release, the difference in time should be 0.

The auto-repeat probably indicates a sticking key. You might try the universal access to suppress the keyrepeats, but you probably need to try cleaning the keyboard or getting a replacement.

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1
  • The keyboard is new and no spill (so far). Agreed, this is not enough to discard keyboard failure. Howerver, it works real fine in Windows 8.1... (see more info in EDIT2 of the problem description) Thank you for your help!
    – JFRivard
    Commented Dec 31, 2014 at 18:35

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