Red Hat Bugzilla – Bug 123273
Erratic mouse behaviour when using KVM switch to return to Fedora box
Last modified: 2007-11-30 17:10:42 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.1) Gecko/20031114 Description of problem: The mouse works fine normally and is set to the following in the XF86Config file: Option "Protocol" "IMPS/2" Option "Device" "/dev/input/mice" but my mouse is connected to the box through a KVM swtich (Belkin Omniview Soho 4-port PS/2 version). When I switch to an alternate box and back again to the Fedora box, the mouse is uncontrollable and behaves erratically. The slightest movement makes the mouse jump randomly around the screen, clicking and selecting items, even though I'm not touching the buttons. Only restarting the PC cures the problem, but re-occurs when you use the KVM switch again. Restarting the X server does not cure the problem. If you switch to tty1 and move the mouse (after the problem has started), you get the following printed out each time you move the mouse (although the number of bytes will vary): psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, throwing 2 bytes away. Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1. Connect PC to KVM switch 2. Switch to alternate box 3. Switch back to fedora Actual Results: Erratic mouse behaviour Expected Results: Mouse performs as normal Additional info: I used to be able to implement a work around in FC1 by setting the Protocol to "MouseManPlusPS/2" with the Device to "/dev/psaux" in the XF68Config file. This unfortunately no longer works. The protocol change has no effect on its own, and if I try and use /dev/psaux, the X server fails to start. From what I can gather /dev/psaux is to be no longer used. The behaviour sounds similar to that in bug report 121877, except I'm not using a laptop, the problem does not go away, and I have no workaround.
I had some feedback from Belkin who stated the following: "This problem can occur when there is a clash between the firmware of the switch and the mouse drivers used. Please try some different mouse drivers." As the psaux driver used to work with the "MouseManPlusPS/2" protocol, is it possible to bring that back?
For your information I have a Microsoft Optical Mouse and a Belkin SOHO 4 ports KVM. It works fine with Windows XP, it used to work with RH9 (although I had to switch from video to text to video mode), but I can't get it to work with Fedora Core 2.
I am also encountering the same problem. Using a Microsoft IntelliMouse PS/2 mouse with a Belkin OmniView 2-port KVM, switching between Windows 2000 Pro and Fedora Core 2 test 3 (Kernel 2.6.6- 1.370). tty1 also gives the same error message "psmouse.c: Wheel Mouse at isa0060/serio1/input0 lost synchronization, throwing [n] bytes away.".
I had the same problem with RH 9, after changing drivers the problem was gone. I now have the same problem with Fedora Core 2 and i cant seem to be able to get rid of it in any way.
I too am (or was) having the same problem. I have a Belkin Optical mouse issues with my Belkin SOHO KVM. Try this - I got it from another similar bug: Add 'psmouse.proto=bare' to the kernel options when booting. It seems to resolve my problem.
Thanks for that, it did the trick. I can now go ahead with upgrading to FC2 on my main box, without worrying about my mouse going crazy.
Keep in mind that, if you have a wheel mouse the wheel will not work.
Reply to comment 1: >Only restarting the PC cures the problem, but re-occurs when you use >the KVM switch again. Restarting the X server does not cure the >problem. This implies that it is a problem either in the kernel driver (which is what X uses nowadays for mice), or a hardware problem. It is possibly a protocol stream synchronization issue caused by the KVM which puts the kernel driver out of sync with the hardware. This problem is very common in many KVM switches. Unfortunately, some KVM switches may work with Linux/X, others may not. I use an ABL Masterview 4 port PS/2 KVM, and it works fine in all OS releases so far, with any hardware I've plugged into it, including the mouse wheel. I use the "IMPS/2" protocol, and use a Logitech Mouseman Wheel, although other PS/2 mice work equally well during testing. Every KVM switch is different however, and some properly save signals and restore, others do not. In some cases it is possible to work around with software/drivers - if direct physical access to the exact same KVM switch and mouse is available to a developer. In other cases it is not possible to work around in software, or may require the KVM vendor to provide patches to enhance a driver to workaround problems with their KVM hardware. This problem isn't as prevalent in Microsoft Windows as it is in Linux, as many people have pointed out in other bugs. The reason the problem does not occur in Windows as much as it does in Linux and other OS's, is because the KVM vendor goes out of their way to ensure Microsoft and other hardware vendors have the proper information to make their input devices work with the particular KVM vendor's KVMs. If you can debug the kernel driver, and provide a data dump of the raw protocol stream coming from the mouse, it may be possible to get the kernel driver to detect an out of sync stream perhaps and reset the hardware. If that is not possible, I recommend filing a bug report in the X.Org bugzilla also in case an upstream X developer has access to your particular hardware, and is able to investigate and debug the issue, and determine if it is possible to work around in software. Hope this helps.
I'm having the same problem using a PS/2 wheel mouse and a Belkin Omni View SE 4-port switch. I'm using a "stock" FC2 kernel, currently compiling 2.6.7 to see if this resolves the problem (as it seems to for some other people). Isn't there some way to force the mouse to re-synchronize? Unplugging the mouse cable from the back of the PC and reconnecting doesn't help.
Just an update to my (former) problem. I was using the stock 2.6.6 FC2 kernel and having the problem described in this bug note exactly. Compiled 2.6.7 and the problem is gone. You guys might want to give it a shot.
The Planet (www.planet.co.uk) KVM-200 switch worked fine with FC1, but I upgraded my system to FC2 and have the same mouse problem (erratic control in X, and same sync error in the console).
I am using the stock: 2.6.7-1.494.2.2smp #1 SMP Tue Aug 3 09:59:49 EDT 2004 i686 i686 i386 GNU/Linux With a Belkin 4 port KVM. The new kernel did not fix the problem. If I unplug my mouse from the KVM and plug it back in, it works again. No fun, but better than rebooting. I have not patched the firmware on my KVM at all. Have those who have been able to resolve the issue patched their firmware?
Dupe of bug 111161?
*** This bug has been marked as a duplicate of 111161 ***
I have the same problem with FC3 and a LinkSys 4port KVM
Changed to 'CLOSED' state since 'RESOLVED' has been deprecated.