On Sat, 2 Feb 2013, Mark Ferrell wrote: > > What version of the kernel are you using? > > The previous output was from a 3.3.8 kernel w/ commit > 50ce5c0683aa83eb161624ea89daa5a9eee0c2ce applied. In general it's better to test with the most up-to-date kernel you can, but in this case I don't think there have been any other significant changes to ohci-hcd since 3.3. > > You should build a test kernel with CONFIG_USB_DEBUG enabled. When the > > problem occurs, post the output from the "dmesg" command -- not the > > contents of the system log file. > > I have already enabled CONFIG_USB_DEBUG, as well as a large number of > other debug options attempting to get something more than the previous > back-trace. I have also enabled CONFIG_OHCI_VERBOSE_DEBUG (overkill?) Almost certainly overkill. :-) > on a few systems in hopes that something useful would be made more > self-evident. > > > This is useless. We need to see what happens when the problem occurs, > > not 2 minutes later. > > Unfortunately the previous back-trace is the only data that shows up. > Even with CONFIG_USB_DEBUG there isn't anything actively arriving in the > kernel log buffer as reported by dmesg. Then the next step is to go into the appropriate subdirectory under /sys/kernel/debug/usb/ohci/ (the one that corresponds to the controller having problems) and see what the files in there say. It may also be possible to get useful information from usbmon, but that's not easy to do if you don't have a good way to trigger the problem. 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
