Fast-pressed key triggers auto-repeat (Ubuntu 14.04 LTS)

14.04 keyboard dell

7,811

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

7,811

JFRivard

Updated on September 18, 2022

Comments

JFRivard over 1 year
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   
```
- ubfan1 over 9 years
  
  If you run xev, then type a key rapidly, do you see the release message: KeyRelease event, serial 33, synthetic NO, window 0x3a00001,...
- JFRivard over 9 years
  
  Interesting. We can see the keypress/keyrelease being repeated forever:
- JFRivard over 9 years
  
  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
- Wilf over 9 years
  
  JFRivard, please edit the output into your question, it is impossible to read in a comment.
- JFRivard over 9 years
  
  I still have this problem. Any help would be appreciated. Please, I am getting desperate... Thank you.
- Dan Dascalescu about 9 years
  
  This is a known problem with Dell laptops - keys randomly repeat on Linuxes such as Ubuntu and Mint - see reddit.com/r/linux/comments/2sg27n/…
- Ivan Borshchov about 4 years
  
  Does it the same for standalone keyboard?
JFRivard over 9 years

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 over 9 years

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 about 9 years

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.