On Wed, 3 Mar 2004, walt wrote: > I'm using linux kernel 2.6.4-rc1. (I don't see this bug with 2.4.x.) > > The problem: when uhci-hcd support is compiled as a module *and* > my USB Zip drive is plugged in during boot, my PS2 mouse stops > working -- I have no cursor movement at all in X. > > If all USB support is compiled into the kernel OR if the USB Zip > drive is unplugged during boot then everything works normally. > > Yes, this is too bizarre to be real. What does the PS2 mouse have > to do with the USB system? I'm hoping someone can at least ask me > some appropriate questions which may shed some light on this bug.
Got to admit, this is one of the weirder bugs I've heard of. One possibility is that the PS2 mouse and the USB controller might share the same IRQ. Perhaps the USB system is then "stealing" interrupts sent by the mouse device. But why this should be affected by compiled-in/module support or whether the USB device is plugged in while booting, I can't imagine. Can you determine whether the mouse and the controller do share the same IRQ line? If they do, further debugging will be in order. Another possibility is that the USB legacy mouse/keyboard support in your BIOS is messed up somehow. That might explain how conditions at boot time could affect the system. I don't know what could be done to fix it, though -- the UHCI driver works exactly the same way and does the same things no matter how you build it. When uhci-hcd is a module and the USB ZIP drive is plugged in at boot, does your mouse fail to work at all? Or does it work initially but then stop working when you install uhci-hcd? (You may have to fiddle with your start-up scripts to find the answer.) Or, suppose you boot with the drive not plugged in, then rmmod uhci-hcd, then plug in the drive, then modprobe uhci-hcd. Will the mouse work then? Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
