USB devices stopped working ... sort of

Tino27 · 08-22-2006, 05:12 PM

Not sure when this happened, but somehow in the last month or so, my laptop has gotten into a state where none of my USB devices (thumbdrive, Blackberry, etc.) work properly anymore. Except for my USB mouse and then only in X (I actually have to plug in the USB mouse after X starts or it won't work).

Now the odd thing about all of this is that when I plug in a device, the /var/log/syslog AND /var/log/messages files will both contain information about the device and and device nodes it should have created. For instance, output from my /var/log/messages file when I plug in my USB mouse:

Code:

Aug 22 18:02:03 butthead kernel: usb 4-1: new low speed USB device using uhci_hcd and address 2
Aug 22 18:02:03 butthead kernel: usb 4-1: configuration #1 chosen from 1 choice
Aug 22 18:02:04 butthead kernel: input: Logitech USB RECEIVER as /class/input/input5
Aug 22 18:02:04 butthead kernel: input: USB HID v1.11 Mouse [Logitech USB RECEIVER] on usb-0000:00:1d.3-1

But if I now do a "lsusb" from the command line, I get nothing -- literally. Same thing goes for my thumbdrive. When I plug it in, messages get logged saying that /dev/sdb1 was created. But when I look in /dev there is nothing there. If I try and create the node manually using "mknod", it then shows up but when I try and mount it I get something about "Device is already mounted or is busy".

I am running Slackware-current on a Dell D610 in case anyone is wondering. Anyone have any thoughts?

Daga · 08-22-2006, 05:19 PM

Which USB spec are these devices designed for? My thumb drive doesn't work until I rmmod ehci_hcd, which probably means I should look for somebody to file a bug report with

Tino27 · 08-22-2006, 10:21 PM

Sorry, I should've said that I've built USB support for these devices into my kernel quite a long time ago (I've been rolling my own kernels since 2.4). I do stay current with the 2.6 kernel series, but I always use my .config files from previous kernel builds so I don't forget or lose any functionality. Things like USB mass storage support and other related drivers should already be in there.

Daga · 08-22-2006, 11:33 PM

I compile my own kernels also... and have some time now :-)

It's been a while since I've played with it, but ehci_hcd is the only one currently compiled as a module. The others are compiled in. If I don't unload that module, my thumb drive refuses to work even though I see the events from the device being plugged in. I don't pretend to know why, but it's the way my system works right now. The USB adapter for the mouse, on the other hand, works fine either way.

Tino27 · 02-02-2007, 09:51 AM

I just wanted to follow up on this as I FINALLY (I didn't realize I had originally posted this so long ago) had time last night to sit down and figure this out. Apparently, even though /etc/rc.d/rc.hotplug is marked as executable and is called in the /etc/rc.d/rc.S script, for some reason that was the culprit. When I plugged in my flashdrive, UDEV was picking up on it, but the handoff to Hotplug wasn't happening and thus, the device nodes weren't being created in /dev. My current temporary workaround is to execute "/etc/rc.d/rc.hotplug start" as root after the computer has finished booting up. After that, all is golden. I'll probably try putting that line in my /etc/rc.d/rc.local script and see if that will consistently start the Hotplug daemon for me.

As an odd little aside, apparently X Windows has something built into it that can utilize a USB mouse, even though the device node was never created for it. If I plugged in my USB mouse before starting X, the mouse wouldn't work. If I started X first and then plugged in my mouse, it would work. Then again, now that I've found this hotplug issue, I no longer have to worry about when to plug in the USB mouse.

Hopefully this will help someone else out there who had a similar problem.