On Wed, 15 Jan 2014 17:04:05 -0500 (EST), Alan Stern wrote: > On Wed, 15 Jan 2014, Dennis New wrote: > > > When listening to my usb-bluetooth audio headset, the usb subsystem > > (I think) on my laptop crashes, the bluetooth/audio is lost, and my > > mplayer program is left in an "uninterruptible sleep" (D) state and > > cannot be killed. The only way to get my usb-audio working again is > > to reboot. > > ... > > > The crash is difficult to reproduce, sometimes it can occur after a > > few minutes of a clean boot, and sometimes after a few days. After > > the audio/usb abruptly stops, the syslog simply says: > > > > kernel: ALSA sound/usb/endpoint.c:501 timeout: still 3 active > > urbs on EP #3 > > > > And then after a few minutes (after enabling some kernel debugging > > options), I get some call traces of the hung task(s), which have > > "ohci_urb_dequeue" in common. > > > > http://dennisn.dyndns.org/guest/pubstuff/debug-usbaudio/crash1.log > > http://dennisn.dyndns.org/guest/pubstuff/debug-usbaudio/crash2.log > > http://dennisn.dyndns.org/guest/pubstuff/debug-usbaudio/crash3.log > > The logs show that the khubd thread is hung, waiting for the ohci-hcd > driver to finish cancelling a transfer. > > > The problem is not with my device, since it occurs with another > > identical piece of hardware. It maybe be a problem with my laptop, > > since my friend does not seem to be experiencing this problem, > > although her laptop does not use ohci-pci. > > > > My usb controllers are: > > > > 1002:4374 00:13.0 USB controller: Advanced Micro Devices [AMD] > > nee ATI IXP SB400 USB Host Controller (prog-if 10 [OHCI]) > > 1002:4375 00:13.1 USB controller: Advanced Micro Devices [AMD] > > nee ATI IXP SB400 USB Host Controller (prog-if 10 [OHCI]) > > 1002:4373 00:13.2 USB controller: Advanced Micro Devices [AMD] > > nee ATI IXP SB400 USB2 Host Controller (prog-if 20 [EHCI]) > > Your first step in attacking this problem should be to use the most > up-to-date kernel available, which at the moment is 3.13-rc8. Be > sure to enable CONFIG_FRAME_POINTER along with CONFIG_USB_DEBUG. > > If the problem occurs again, collect a copy of the output from the > dmesg command (_not_ a copy of the system log). Then go into > /sys/kernel/debug/usb/ohci and collect copies of all the files in the > two subdirectories. > > It may be necessary to apply some debugging patches to get more > information. Erase my last post, the problem still exists with 3.13-rc8. I did enable FRAME_POINTER and USB_DEBUG, but forgot DEBUG_FS. (I will do that now.) There doesn't appear to be anything more informative in the dmesg/syslog outputs. (My dmesg output was truncated, but basically the same as my syslog.) http://dennisn.dyndns.org/guest/pubstuff/debug-usbaudio/crash4.log Although, as you can see, it's difficult to reproduce -- my 3.13-rc8 was running just fine for almost a week! -- 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
