A USB 1.1 video device may not work correctly if you plug the USB 1.1 video device into a USB 2.0 hub on a Windows XP-based computer (899860)


The information in this article applies to:

  • Microsoft Windows XP Home Edition
  • Microsoft Windows XP Professional
  • Microsoft Windows XP Tablet PC Edition
  • Microsoft Windows XP Media Center Edition

SYMPTOMS

If you plug a universal serial bus (USB) version 1.1 video device into a USB version 2.0 hub, the USB video device may not function correctly. The video image may be garbled, or the video image may not be displayed at all.

CAUSE

This problem occurs because the Windows XP host controller driver for Enhanced Host Controller Interface (EHCI) USB controllers does not enforce this ordering requirement. The USB 2.0 specification requires that the complete-splits for different isochronous transfers be in the same order as their respective start-splits. The host controller driver is responsible for enforcing this ordering rule. Because the Windows XP host controller driver for EHCI USB controllers does not enforce this ordering requirement, the USB 2.0 hub may fail the complete-split transfer requests from the host.

WORKAROUND

To work around this issue, bypass the USB hub and plug the camera directly into a USB 2.0 port on the Windows XP-based computer.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Modification Type:MajorLast Reviewed:6/28/2005
Keywords:kbtshoot kbprb KB899860 kbAudEndUser
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