Bugzilla – Bug 130990
mouse loses control through d-link kvm switch
Last modified: 2006-01-11 11:05:33 UTC
I have a 4 port KVM switch that I use with a few servers (1 monitor, 1 keyb & 1 mouse to manage all machines). I installed 10.0 final version (not oss) and whenever I switch the KVM port to another computer connected to it and then return to the suse computer and try to move the mouse slowly, the mouse cursor starts moving erraticaly on the screen as if someone keeps all buttons pressed and moves it around madly (it does right clicks, left clicks, scrolls and so on, whenever the cursor is on a relevat screen part where such actions can be done). Restarting the X server with ctrl+alt+backsp doesn't help. Rebooting and keeping the KVM switch only to the suse computer shows no problems of this issue... I had something related a while ago while trying to install suse linux on a machine connected through kvm switch, it never detected the video card properly and only wanted to install in text mode... Daniel
If restarting the X server doesn't help, this is a kernel mouse driver issue. Even if the monitor is not detected, installation should work graphically. In your case it seems that the bios did not have a framebuffer mode (maybe a i815?). For i815 that has been fixed. Video card detection has nothing to do with kvm switches.
Well, I used to have such problems with my KVM switch, too. I didn't experience them lately, I don't know why. When the problem occurred not even my protocol detection code could do anything useful with the data delivered from the mouse. Why the problem occured in the first place was impossible to find out. I'm not sure if there is anything at all we can do. Neither im kernel nor in X.
I agree. I therefore close this one as WONTFIX.
I have had this problem with a Belkin switch as well. From the research I've done, I've found that it does appear to be a kernel level issue. From posts I've found RH appears to have fixed the issue at some point, though I've not verified that. Also, Suse 9.3 (installed and live DVD) both do not have this problem beyond the first mouse movement upon swtiching back. The resync works there. I cannot find any kernel compile options that are different and my programing skills do not allow me to check the code.
Sorry, forgot to click on the reopen last time.
*** Bug 132045 has been marked as a duplicate of this bug. ***
I'm closing this. If someone is able to fix this, please reopen it.
There are bzillions of different KVM switch models around and a lot of them are broken in one way or the other. Mine behaves well - so I cannot reproduce these problems. Good for me. Bad for the others who are not so lucky.
If anyone could send me a KVM that makes trouble I could see if it's fixable.
Something that I found that seems to work with the Belkin switches that I've tried this on. Passing the option 'psmouse.resetafter=3' seems to fix the issue for me. The number looks for a particular ammount of errors from the mouse and resets the protocol after that many errors are found. The scrollwheel continues to work as well. I don't have a D-Link switchbox to test this on, but I would be interested if it works. Also if anyone knows of a reason not to use this as a solution that would be great to know as well.
'psmouse.resetafter=3' --> reassiging to Vojtech :-)
This option was added exactly for working around problematic KVM's. It's harmless and can even be set to a lower value (even 1 usually works without adverse effects, and synchronizes faster). If it solves your problem, I think we can close this bug.
Closing, a workaroun for problematic KVM's exists.