Alan Stern wrote: (Add uvcvideo maintainer to CC) > [ 420.737748] usb 1-5: link qh1024-0001/f6ffe280 start 1 [1/0 us] > > > The periodic schedule was enabled here. > > >> [ 420.737891] usb 1-5: unlink qh1024-0001/f6ffe280 start 1 [1/0 us] >> > > And it was disabled here. Do you have any idea why the uvcvideo driver > submits an interrupt URB and then cancels it 150 us later? The same > thing shows up in the usbmon traces. > > >> [ 420.741605] usb 1-5:1.0: uevent >> [ 420.741957] usb 1-5: uevent >> [ 420.745592] usb 1-5:1.0: uevent >> [ 420.807880] ehci_hcd 0000:00:1d.7: reused qh f6ffe280 schedule >> [ 420.807894] usb 1-5: link qh1024-0001/f6ffe280 start 1 [1/0 us] >> > > Now ehci-hcd tried to re-enable the periodic schedule. Note that > this is 70 ms after it was supposed to be disabled. > > >> [ 420.808780] ehci_hcd 0000:00:1d.7: force halt; handhake f7c6a024 >> 00004000 00000000 -> -110 >> > > This error message means that the disable request from 70 ms earlier > hasn't taken effect. It looks like a nasty hardware bug -- the > controller is supposed to disable the schedule no more than 2 ms after > being told to do so. > > Has this device ever worked with any earlier kernels? > I only tried 2.6.30.9 and 2.6.31.4, both of them is affected by the same problem but sometimes it works without a problem so I think that this can be interpreted as *at-least-working* on those kernels from time to time. > A little more debugging information could confirm this. After the > error occurs, go into /sys/kernel/debug/usb/ehci/0000:00:1d.7 and post > a copy of the "registers" file. If there's anything of interest in the > other files, post them too. > OK I'll look at them tomorrow, Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
