Sporadically erroneous keystroke repetitions

[Colin Guthrie]

'Twas brillig, and Tomasz Torcz at 15/11/09 00:11 did gyre and gimble:
> On Sat, Nov 14, 2009 at 05:42:47PM -0500, Gene Heskett wrote:
>> On Saturday 14 November 2009, Nix wrote:
>>> On 11 Nov 2009, Oliver Block spake thusly:
>>>> I sporadically encounter repetitions of my keystrokes. What happens is
>>>> the following:
>>>>
>>>> I press any key, say "a", and instead of getting just one "a" I get many.
>>>> Not just a few but it is like if I would keep pressing the key. Then I
>>>> have problems stopping this. Often it does not stop itself.  I cannot
>>>> tell what I have done exactly in these situations, but normally I tried
>>>> to press other keys to make this stopping. I guess I often used Esc.
>>>> Then normally it stops and afterwards everything is fine. But
>>>> this happens quite regularly (once every few hours) and it is very
>>>> annoying. This behaviour is somewhat new (since a few month). I am not
>>>> sure, but maybe it started after switching from a Ubuntu system to
>>>> Debian lenny now. The installed xorg has version 1:7.3+20.
>>> Are you using kernels 2.6.31--2.6.31.4 on an SMP system or with PREEMPT
>>> enabled? If so, this is a Linux kernel bug, fixed in 2.6.31.5.
>> I wouldn't go so far as to say that its fixed, I've not noticed it 
>> ssssssssstooooping doing that yet, currently at 2.6.32-rc7.
>> ^^^^^^^^^^^example, I fixed the rest of them, but its been a PIMA for 2 years 
>> now, over 2 motherboards and 5 or 6 keyboards, its never really stopped.
> 
>   I can concur, this is very annoying. It is happening for few years now,
> on different kernels and architectures. But always on Linux.
> 

A consistent problem I've seen with key repeats for a while now (years) 
is that of when I try to type something immediately after resuming from 
suspend. Some time ago the resume cycle took a while for the display to 
come back so usually I didn't type anything for a while after resuming. 
But now with KMS, my display comes on immediately (yay!) which tempts me 
to type in my password pretty quickly. If I do, the key repeats start 
and quite literally don't stop! I can't switch VTs or find any way to 
recover this. Usually I just power cycle.

Is there anything I can do to debug (e.g. via SSH) when this situation 
arises? I'm on 2.6.31.5, still on xserver 1.6.x but will be upgrading to 
the latest packages all round today!

Col

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Colin Guthrie
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http://colin.guthr.ie/

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