Hello, On 01/23/2013 01:01 PM, Frank Lömker wrote: > We have a somewhat UVC compliant USB2 camera connected to a USB3 port. > It works mostly great. But when we SIGKILL the program which opened the > device, the corresponding host controller dies and the system must be > rebooted to access the USB port again. If the program closes the device > normally and then ends, everything works correctly. > > In the error case we get the following messages. The uvcvideo lines are > additional debug messages which we added during debugging this problem: > > [ 130.812349] uvcvideo: uvc_v4l2_release > [ 130.812352] uvcvideo: uvc_v4l2_release has_privileges > [ 130.812355] uvcvideo: uvc_uninit_video start > [ 130.812536] uvcvideo: uvc_uninit_video done > [ 131.113099] uvcvideo: usb_set_interface start > [ 131.113121] xhci_hcd 0000:00:14.0: Signal while waiting for configure endpoint command > [ 131.113163] usb 3-1: Not enough bandwidth for altsetting 0 > [ 131.113165] uvcvideo: usb_set_interface done > [ 131.416625] uvcvideo: uvc_queue_enable start > [ 131.416630] uvcvideo: uvc_queue_enable done > [ 131.720344] uvcvideo: uvc_v4l2_release 2 > [ 131.720348] uvcvideo: uvc_v4l2_release 3 > [ 131.720356] xhci_hcd 0000:00:14.0: ERROR no room on ep ring > [ 131.720359] xhci_hcd 0000:00:14.0: ERR: No room for command on command ring > [ 136.728324] xhci_hcd 0000:00:14.0: xHCI host not responding to stop endpoint command. > [ 136.728330] xhci_hcd 0000:00:14.0: Assuming host is dying, halting host. > [ 136.728344] xhci_hcd 0000:00:14.0: HC died; cleaning up > [ 136.728364] usb 3-1: USB disconnect, device number 2 > [ 136.728378] uvcvideo: uvc_v4l2_release 4 > [ 136.728388] uvcvideo: uvc_v4l2_release 5 > [ 136.768486] xhci_hcd 0000:00:14.0: Slot 1 endpoint 2 not removed from BW list! > > I.e. the uvc driver calls > > usb_set_interface(stream->dev->udev, stream->intfnum, 0); > > during it's uvc_v4l2_release() execution. This fails with > [ 131.113121] xhci_hcd 0000:00:14.0: Signal while waiting for configure endpoint command > [ 131.113163] usb 3-1: Not enough bandwidth for altsetting 0 > If we remove this usb_set_interface() call everything seems to work > correctly, no error messages are in the log, and the USB3 port > remains accessible. > > But that's probably not the right solution. At least I, with my very > limit knowledge about USB and xhci, don't see an error in calling this > here during the release operation. So we looked further. The call > chain which is performed starting from usb_set_interface() is: > > usb_set_interface() > ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt); > ret = hcd->driver->check_bandwidth(hcd, udev); > xhci_check_bandwidth() > ret = xhci_configure_endpoint(xhci, udev, NULL, false, false); > timeleft = wait_for_completion_interruptible_timeout( > cmd_completion, XHCI_CMD_DEFAULT_TIMEOUT); > > It seems to me as if wait_for_completion_interruptible_timeout() > stops because of the SIGKILL which the process received before. > Changing the wait_for_completion_interruptible_timeout() in > xhci_configure_endpoint() to wait_for_completion_timeout() fixed > the problem for us as well. No error messages occur in the log > and the USB3 port remains accessible. Don't now if this is anything > near the right solution to this problem. > > Attached is a patch for this, probably wrong, "solution" and the > kernel logs starting shortly before the SIGKILL and ending shortly > after the HC died message. The kernel logs where generated with > CONFIG_USB_DEBUG and CONFIG_USB_XHCI_HCD_DEBUGGING turned on. > Additionally uvcvideo was loaded with trace=255. > > During debugging this problem we used the kernels 3.2.0-35-generic > from Ubuntu 12.4 and the latest vanilla kernel from the 3.6 series, > version 3.6.11. The patch is against version 3.6.11. Just verified that kernel 3.8.0-rc4 does not change anything. When using SIGKILL the vanilla kernel fails with the same messages as kernel 3.6.11. With the patch applied the 3.8.0 kernel seems to work as well. Regards, > We use an AAEON IMBM-B75A mainboard with an Intel B75 chipset, > bios version 0601. The camera is a "DFK 42AUC03" from > "The Imaging Source Europe GmbH". > > Does anybody know what's the right solution for this problem? > Or is the patch even correct? > > Thanks in advance, -- Dr. Frank Lömker Leiter Softwareentwicklung E-Mail: Frank.Loemker@xxxxxxxxxx Tel : +49(0)3677-46929-63 Internet: www.isa.de.com ISA Institut für Serviceautomation GmbH & Co. KG Ziolkowskistr. 8, 98693 Ilmenau phG: ISA GmbH, Ilmenau (AG Jena, HRB 306708) Geschäftsführer: Dipl.-Ing. (FH) Jürgen Utschig Ust-IdNr. DE 239745996 ILN 43 99901 84388 2 Amtsgericht Jena HRA 301735 HRB 306708 Member of SIELAFF GROUP -- 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
