On Mon, Jul 22, 2013 at 03:58:19PM +0800, Shuduo Sang wrote: > On Mon, Jul 22, 2013 at 3:23 PM, George Cherian <george.cherian@xxxxxx> wrote: > Yes, I run below script to capture picture. > > #!/bin/bash > # camera_stress.sh > # Testing the camera by BinLi > > for ((i=0; i<10 ; i++)) > do > fswebcam --no-banner -r 352x288 -d /dev/video0 test_$i.jpg > done > > It will randomly fail at later loops. The fail rate about 20%~30%. When it fail, > I can see error messages by dmesg as below: > > [ 68.171039] xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr > not part of current TD > [ 68.175030] xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr > not part of current TD > [ 68.179026] xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr > not part of current TD > [ 68.180082] usb 3-12: USB disconnect, device number 4 > [ 68.450459] usb 3-12: new high-speed USB device number 5 using xhci_hcd > [ 68.477960] usb 3-12: New USB device found, idVendor=5986, idProduct=0397 > [ 68.477964] usb 3-12: New USB device strings: Mfr=1, Product=2, SerialNumber=0 > [ 68.477966] usb 3-12: Product: Integrated Camera > [ 68.477968] usb 3-12: Manufacturer: Vimicro corp. > [ 68.479107] uvcvideo: Found UVC 1.00 device Integrated Camera (5986:0397) > [ 68.479821] input: Integrated Camera as > /devices/pci0000:00/0000:00:14.0/usb3/3-12/3-12:1.0/input/input15 > [ 321.389721] type=1400 audit(1374214638.182:29): apparmor="DENIED" > operation="capable" parent=1 profile="/usr/sbin/cupsd" pid=1232 > comm="cupsd" pid=1232 comm="cupsd" c > apability=36 capname="block_suspend" That's a different issue. The log shows that your USB webcam disconnects, and that's why your script fails. Then the device re-connects. Do other USB devices work after the camera disconnects? Does the webcam itself work (at least for a while) after you stop and restart the script? (Note that after a disconnect, the webcam may be present on /dev/video1 instead of /dev/video0, because your script had /dev/video0 open when the webcam re-connected.) > >> Then I manually applied George's patch against 3.10.0 but the issue > >> still happen when I use > >> camera to capture picture. > > > > Can you explain what is the exact issue you face after applying the patch? > > Are you still getting > > > > "ERROR Transfer event TRB DMA ptr not part of current TD" > > Yes, after I applied your patch manually, I still getting this error. > Seems fail rate is same. I'm still going to apply George's patch, because it does fix a different issue. I'm not sure if there's anything software can do if the webcam keeps disconnecting. That's usually an electrical issue. Have you tried a different USB cable? If the webcam is behind a hub, have you tried connecting it directly to the computer's roothub? If it's attached to the roothub, have you tried putting it behind an external hub? If none of that works, I can look at your logs, and try to figure out if there's anything software can do. Can you recompile your kernel with George's patch and CONFIG_USB_DEBUG and CONFIG_USB_XHCI_HCD_DEBUGGING turned on? Please send me the log from just before you start your script to when the device disconnects. Sarah Sharp -- 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
