[Hardy] Caps Lock causes keys to repeat

Bug #213669 reported by Harvey Muller
22
This bug affects 3 people
Affects Status Importance Assigned to Milestone
linux-ports-meta (Ubuntu)
Invalid
Undecided
Unassigned

Bug Description

Binary package hint: xserver-xorg

Problem:

Entering [Caps Lock] and then any other character causes the second key to be repeated continually, until the [Caps Lock] key is hit again. I discovered this problem after learning to use emacs, and subsequently switching the [Caps Lock] and [Ctrl] keys. This error occurs in any text editor, the command line, or any form field that accepts input.

To reproduce:

It doesn't occur in every instance, but can reliably be reproduced within 20 - 25 tests. To test, either open a terminal or any editor, and then depress the [Caps Lock] key immediately followed by a character. I used the 's' and 'x' keys, as these are the two that commonly reproduce the error using emacs with the [Caps Lock] and [Ctrl] keys swapped. Once the key starts repeating, you can halt it by hitting the [Caps Lock] key again.

Research:

I restarted the machine and booted to a root console, without X. I could not reproduce the error in an environment without X. I then started X by running xinit, and was able to reproduce the error. This is how I generally isolated it to X. I do not know how to isolate it further.

This may remotely be related to Bug #74006 Cap lock key stuck in cap lock - https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/74006

Revision history for this message
Harvey Muller (hlmuller) wrote : Re: [Bug 213669] Re: [Hardy] Caps Lock causes keys to repeat

Greetings Timo,

After reading through the lengthy bug you have marked this a duplicate of (124406), I have a question.

Although there is a chance they may be related, the symptoms experienced in Bug 213669 are not reported in the bug you have tied this to. I am not experiencing any of the other issues and cannot reproduce them, only the Caps Lock key causes repeats, which can be halted by hitting the Caps Lock key.

I understand however that linking 213669 to 124406 may be a method to tie all like issues together for resolution. Is this the case?

If so, I'll start watching bug 124406, if not I respectfully request that bug 213669 be unlinked from 124406.

Best regards,

Harvey

----- Original Message ----
> From: Timo Aaltonen <email address hidden>
> To: <email address hidden>
> Sent: Friday, April 11, 2008 4:00:44 AM
> Subject: [Bug 213669] Re: [Hardy] Caps Lock causes keys to repeat
>
> *** This bug is a duplicate of bug 124406 ***
> https://bugs.launchpad.net/bugs/124406
>
> ** This bug has been marked a duplicate of bug 124406
> Keyboard keys get stuck and repeat (Feisty, Gutsy)
>
> --
> [Hardy] Caps Lock causes keys to repeat
> https://bugs.launchpad.net/bugs/213669
> You received this bug notification because you are a direct subscriber
> of the
> bug.

Revision history for this message
Timo Aaltonen (tjaalton) wrote :

please do monitor that one, and shout if the issue persists when that bug is fixed.

Revision history for this message
Mark Schreiber (mark7) wrote :
Download full text (19.5 KiB)

Looks like Bug 213669 has been closed -- too many unrelated problems being reported there, which I think is probably a good call. I'm going to extract the relevant posts there and stick them here.

Quick summary of what I've been able to find: The problem is still present in Ubuntu Jaunty. Both Harvey and I are using Dell Inspiron 1420 laptops, and both of us have swapcaps enabled. On both systems, the kernel knows that a key (I usually see "S", as I hit caps-lock-s to get C-x C-s frequently in emacs) is down, and does not generate repeat events for it, but the "key up" event does not appear in evdev, so this can be narrowed to a kernel problem somewhere above the hardware driver level. On my system, the situation is only cleared up when another key is hit -- it does not clear up after a certain amount of time. I see no keydowns being lost. Because console applications appear to rely on kernel-generated auto-repeats rather than evdev key-ups, they "don't see" this problem -- the kernel does *not* generate auto-repeat events with this bug. Instead, xorg is never told that the key is up and thus generates auto-repeat events.

Extracted posts:

===
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/124406/comments/125
 Harvey Muller wrote on 2008-04-16: (permalink)

Cruncher and wilderjds,

Cruncher:

The bug (#213669) I experience is not as described here, the repeating does not stop by itself. It is also not similar to #194214, in that I cannot reproduce those problems. When I experience the bug, simply hitting any other key after the repeats begins, stops the repeats.

I am running 2.6.24-16-generic and still experience the repeat bug. I do not believe my specific bug is this one, but Timo Aaltonen has deemed it a duplicate.

wilderjds:

I only get stuck repeat keys when using the Caps Lock key, holding it down then pressing another key. The second key pressed will stick frequently but not all the time.

The bug isn't triggered by cpufreq changes in my case. It happily causes repeats when both processors are stable at the low freq. And

I am able to reproduce the stuck repeats in a minimal X environment (i.e. no compiz, window manager, etc.)

===
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/124406/comments/127

Mark Schreiber wrote on 2008-04-16: (permalink)

Not certain whether this is the same problem. It sounds awfully similar, except for the fact that I haven't seen my behavior "clear up" in a few seconds, as some have mentioned. With Gutsy on an Inspiron 1420 laptop, I sporadically see keys "stick" when using the built-in keyboard (I haven't tried external keyboards). Hitting another key clears up the situation immediately (which makes sense -- the internal keyboard is USB, and USB interface keyboards send the whole keyboard state on any keypress). Happens most frequently with "s" at at the end of a line in emacs, presumably since I pause in typing and allow enough time for the key repeat to kick in. I have not tried working on the Linux console to see whether it is affected as well -- it does happen in xorg. I type heavily, since I'm coding much of the day, and get this probably at least five or six times a day.

O...

Revision history for this message
Harvey Muller (hlmuller) wrote :

Mark, and anyone that follows:

In bug 124406, I indicated the key repeat issue was resolved. It is in fact not resolved, but the key repeat problem is triggered now very rarely. To repeat <pun intended> the problem is still present.

Best regards,

Harvey

p.s. I also confirm Mark's observation, that the 's' key is a common repeater.

Revision history for this message
Mark Schreiber (mark7) wrote :

Unmarking as duplicate of Bug 124406 (now that I've figured out how to do so in Launchpad).

Bryce Harrington (bryce)
affects: xorg (Ubuntu) → xserver-xorg-input-evdev (Ubuntu)
Bryce Harrington (bryce)
tags: added: hardy
Revision history for this message
Michael Richardson (mcr-sandelman) wrote :

My experience (with CAPS-LOCK as an additional CTRL key) is that the CTRL key stays down.
xkbwatch confirms this. A vt control switch (CTRL+ALT + F4) and then back to X (ALT+F7) solves my problem.
But, it's very annoying.
I too, experience this in Xemacs mostly, where I hold the "CTRL" (labelled CAPSLOCK) down for long periods of time.

Revision history for this message
Mark Schreiber (mark7) wrote :

I've seen this in Jaunty and am seeing it currently in Karmic.

tags: added: jaunty karmic
Revision history for this message
Cruncher (ubuntu-wkresse) wrote :

http://ajaxxx.livejournal.com/62378.html presents a possible explanation that seems quite relevant, and sounds as if it could be the true source of many of the known keyboard glitches.
It would also explain why nobody experiences the bug in the console tty, only in X.

Revision history for this message
Mark Schreiber (mark7) wrote :

Cruncher: that might explain some issues that someone else is seeing, but I'm confident that it's not causing what I'm seeing. In comment #3, I summarize some of my own troubleshooting. od -x on /dev/input/event1 sees the problem as well, and od uses blocking I/O, not SIGIO. Whatever is broken is inside the kernel input code -- it isn't an xorg problem.

Hmm, actually, that means that this bug is miscategorized -- I should recategorize.

affects: xserver-xorg-input-evdev (Ubuntu) → linux-ports-meta (Ubuntu)
Revision history for this message
Harvey Muller (hlmuller) wrote :

I no longer own this hardware and cannot confirm resolution. Bug may be closed.

Revision history for this message
Mark Schreiber (mark7) wrote :

I still do have my hardware. Bug is still present in natty.

Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in linux-ports-meta (Ubuntu):
status: New → Confirmed
Revision history for this message
penalvch (penalvch) wrote :

Harvey Muller, this bug report is being closed due to your last comment https://bugs.launchpad.net/ubuntu/+source/linux-ports-meta/+bug/213669/comments/10 regarding you no longer have the hardware. For future reference you can manage the status of your own bugs by clicking on the current status in the yellow line and then choosing a new status in the revealed drop down box. You can learn more about bug statuses at https://wiki.ubuntu.com/Bugs/Status. Thank you again for taking the time to report this bug and helping to make Ubuntu better. Please submit any future bugs you may find.

Changed in linux-ports-meta (Ubuntu):
status: Confirmed → Invalid
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