-   Linux - General (
-   -   Unlocking a "frozen" keyboard / mouse (

J.W. 11-21-2003 02:38 AM

Unlocking a "frozen" keyboard / mouse
On rare occasions (maybe once every 3 months) I manage to fubar my system such that neither the keyboard nor the mouse is responsive, very much like what happens with my Windows box at the office about every few days. This typically only happens when I am running a lot of apps (multiple Mozilla windows, multiple console windows, Evolution, XMMS, Wine, etc) but at the same time, my rig has 1G of Kingston RAM so I'm not expecting it to hang. What's frustrating is that if either the keyboard or the mouse worked, I could easily get out of this situation. Other facts: I've got a Belkin 2 port KVM, and frequently toggle between boxen (both running Slack v9.0) and if I do get into this infrequent condition, my monitor freezes too (ie, the clock no longer ticks, etc). The thing is just hosed, and the only way I've been able to get out of it is a by doing a hard reboot.

Attempting to Alt-F2, or alt-ctl-del to close the session, etc, is useless, because as I mentioned, it's as if the keyboard is disconnected. Likewise, I've got an optical mouse, and in this frozen state the light turns off as if it's disconnected. I've tried un- and re-plugging the mouse and/or the keyboard on the KVM, but that doesn't have any effect. If anyone has any suggestions on how to revive either the keyboard or mouse, I'd definitely be interested in any feedback. This has only happened twice the entire year, so it's not as if it's a major problem, but if there's a way to resolve it without rebooting I'd definitely be interested in learning. Thanks, sorry for the long post. -- J.W.

born4linux 11-21-2003 02:56 AM

had that scenario mostly with Red hat machines. if it's in a network, try pinging it or try to login. if that doesn't respond, there is no other thing to do but reboot.

try checking your xsession-error log files in your home directory for any hints.

tek8one 11-21-2003 10:07 AM

I have experienced several similar issues with belkin kvms before. I have 2 units, a 2-port (without power cord) and a 4-port (with power cord). I got rid of the 2 port because it was constantly losing the mouse when switching between 2 Windows 2000 Pro boxes. Sometimes, i wouldn't even get a mouse at startup! I replaced it with a nice Linksys kvm (with power cord). I have had no problems what-so-ever for 6 months now. Unfortunately, I still have the 4-port belkin kvm. Most of the time it works fine, but on a few occasions, the mouse goes crazy when I switch to Linux (never seen it happen with windows boxes).

Anyways, I'd suggest getting a different brand kvm with a power cord if you can afford it. The units that rely on power from PS/2 or USB aren't as reliable as ones with a cord. As I said earlier in the post, I suggest Linksys. Works great and looks good to boot. Their 4-port kvm runs around $120 last I checked.


LunaticManiac 11-21-2003 11:03 AM

You can find the Linksys KVM around 80 bucks, but you've gotta look real hard, I've found them for even cheaper, around 40, but that's because I had a couple of friends who worked at places who let me know when things were up cheap.

As far as the keyboard/mouse freeze goes, I've had a very similar problem actually occur in the last couple of days...and, yes..go figure, I was running the new Redhat. My systems a bit low key, I was only running the up2date program and mozilla before the system locked up and mouse and keyboard went unresponsive. The strange thing was that the caps lock and scroll lock lights flashed at might be a different problem than what your experiencing, so it just all depends...

I ended up having to do a hard reboot, but there wasn't anyway around it. Good luck with your system though.

aaa 11-21-2003 12:11 PM

Whenever my system 'freezes' I can use my pc's acpi power management to shut down properly with the power button. Another thing you might want to look into is the SysRq key. I think if you enable it in the kernel, the kernel will respond to that key no matter what (even if X is hogging it up & freezes).
Edit: I can also reprogram the power button to do whatever I want.

J.W. 11-22-2003 01:12 AM

Thanks everyone for the feedback. I definitely will consider ditching the Belkin 2-port in place of a Linksys 4-port, as I am looking hard at getting a laptop in the near future and therefore would outgrow the 2 port anyway. I also have certain questions regarding Belkin in general, if you are interested you may check this out on Slashdot:

In any event this lockup issue is pretty small potatoes, but considering how totally stable Slack is, and how stoked I am about my rig in general (since it has never let me down) this rare "freeze" condition is just totally out of character. If an external device like the KVM could be the cause, spending some bucks on a replacement might be justified. Thanks again for the tips on the Linksys.

aaa - your post is interesting but if I'm understanding it correctly, let me clarify that the issue isn't that X seems to end up hogging 100% of the CPU, but rather, the keyboard and mouse act (for all practical purposes) as if they are no longer connected to my box. The behavior is exactly as it would be if you were to just pull the plugs for the keyboard and mouse. After thinking about this some more, I'm thinking that there probably isn't anything I can do from an input device to break this frozen condition, as those devices might as well not exist anymore when this happens. In any event, can you describe how to assign your own functions to the power button? That sounds really cool. -- J.W.

JZL240I-U 11-24-2003 02:57 AM

I had some freeze-ups due to crashes in KDE (Konqueror, I believe). Though I can't offer a remedy, just as an aside I was very happy to have a journalling file system (Reiser in my case). If you don't use them already you might want to consider them now ;).

meldroc 11-24-2003 03:12 AM

If you have another system handy, you can use it to ssh into your hosed box. Then you can restart X, shut down gracefully, etc.

JZL240I-U 11-24-2003 03:26 AM


Originally posted by meldroc If you have another system handy, you can use it to ssh into your hosed box. ...
I don't. Not to mention that theses boxes would have to be connected by hardware and system requirements beforehand. Would it not be easier to just have a second keyboard? I mean, we have a multiuser system -- so login as a second user and off we go -- I just would not know how to go about it and how to set up the startup routine so I could use a single screen (no room for two CRTs).

8nasmith 11-24-2003 06:25 AM

are wirless keyboard and mice compatable with linuxc i dont want to risjk it

8nasmith 11-24-2003 06:26 AM

sorry about my spelling

ive said that a lot

JZL240I-U 11-24-2003 07:06 AM


Originally posted by 8nasmith
are wirless keyboard and mice compatable with linuxc i dont want to risjk it
USB is supported, so that would be a viable alternative.

meldroc 11-25-2003 03:55 AM

Another idea: If you could find an old VT-100 terminal or put together a frankenbox with some sort of terminal emulation, you can plug it into your Linux box's serial port and log in that way.

I'm really not sure if Linux knows how to deal with multiple mice or multiple keyboards.

As for wireless, I use a wireless Logitech mouse with the receiver plugged into USB on my system. Works great. I see no reason why a wireless keyboard wouldn't work.

All times are GMT -5. The time now is 04:46 AM.