On Thu, 23 Jul 2009, Matthijs Kooijman wrote: > (Please CC me, I'm not subscribed) > > Hi all, > > I've been having some problems with my USB setup, which used to be working > before. I think trouble started when I enabled CONFIG_USB_EHCI_TT_NEWSCHED to > get enough bandwidth for my new USB sound card, though things worked properly > at first. I changed a few other things in my setup (new kernel, new USB hub), > and now things are breaking. The good news is that it's completely > reproducible. > > Right now, I'm running 2.6.31-rc4. I have an USB 2.0 hub connected. When I > plug in my wireless keyboard receiver into the hub, things half work (I'm > seeing "drivers/hid/usbhid/hid-core.c: can't reset device, > 0000:00:13.2-1.1.3/input0, status -32" sometimes, though this seems dependent > on the output port used). As soon as I unplug my device, I get: > WARNING: at drivers/usb/host/ehci-hcd.c:906 ehci_urb_dequeue+0x1e1/0x200 > [ehci_hcd]() > (See below for the full trace). After this warning, the machine locks up > (sysreq still works, but the console seems locked up). This happens reliably > with two different hubs I've tried. I'll have a go with other devices later > on. Connecting the keyboard receiver directly to the machine works fine. > > > I have been trying to get a bit more info, but not very succesful as of yet. > I've enabled USB debugging, but that doesn't give me much more output (or > should I look in debugfs?). I've tried running the stacktrace through > ksymoops, but I'm not so sure that's needed (I read that 2.6 doesn't use > ksymoops, but also that it used to be in the kernel tree, and that 2.6 doesn't > have /proc/ksyms, but /proc/kallsyms, but ksymoops doesn't like kallsyms...) > > I'm willing to invest some time debugging this, but I'm at a loss on where to > start. I'll try turning off CONFIG_USB_EHCI_TT_NEWSCHED again, to see if that > removes the problem, but other suggestions are very welcome! See this thread: http://marc.info/?t=124807676700001&r=1&w=2 You can try repeating some of the tests described there. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
