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[Brad Figg <brad.figg@xxxxxxxxxxxxx>]

This bug is missing log files that will aid in diagnosing the problem.
>From a terminal window please run:

apport-collect 1227583

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable
to run this command, please add a comment stating that fact and change
the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the
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** Changed in: linux (Ubuntu)
       Status: New => Incomplete

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https://bugs.launchpad.net/bugs/1227583

Title:
  Webcam USB bandwidth problem when connected using USB2.0 hub

Status in “linux” package in Ubuntu:
  Incomplete

Bug description:
  I have a strange problem with webcams Creative Live! Cam Sync HD VF0770 (041e:4095).
  I have two of them.
  I would like to stream simultaneous streams with 1280x720 at 5fps.
  When connected directly to laptop, I can do this, actually I can stream the same resolution at 30fps.
  But, when I plug both of them using USB hub (Gembird 7-port USB2.0 powered hub), I can stream one camera.
  But when starting the second one, the dmesg throws error

  uvcvideo: Failed to submit URB 0 (-28).

  and the mjpg-streamer shows

  Unable to start capture: No space left on device

  From other defects reported here I understand that this is a problem with USB bandwidth allocation.
  However, the USB for both cameras seems to be set at 480Mbit - this is the output of lsusb -v -t

  /:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/5p, 480M
      |__ Port 4: Dev 19, If 0, Class=hub, Driver=hub/4p, 480M
          |__ Port 2: Dev 24, If 0, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
          |__ Port 2: Dev 24, If 1, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
          |__ Port 2: Dev 24, If 2, Class=audio, Driver=, 480M
          |__ Port 2: Dev 24, If 3, Class=audio, Driver=, 480M
          |__ Port 3: Dev 20, If 0, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
          |__ Port 3: Dev 20, If 1, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
          |__ Port 3: Dev 20, If 2, Class=audio, Driver=, 480M
          |__ Port 3: Dev 20, If 3, Class=audio, Driver=, 480M
          |__ Port 4: Dev 21, If 0, Class=hub, Driver=hub/4p, 480M

  I tried lowering the resolution for both cams to 320x240, minimum fps for the camera is 5, so I can't go any lower than that.
  Can anyone, please, point me out how can I investigate this problem further?

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