Q264946: PRB: Bandwidth Leak of USB Device on Surprise Removal

Article: Q264946
Product(s): Microsoft Windows NT
Version(s): WINDOWS:
Operating System(s): 
Keyword(s): kbDDK kbOSWin2000 kbOSWin98 kbDSupport kbUSB
Last Modified: 28-OCT-2000

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The information in this article applies to:

- Microsoft Windows 2000 Advanced Server 
- Microsoft Windows 2000 Server 
- Microsoft Windows 2000 Professional 
- Microsoft Windows 98 
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SYMPTOMS
========

Universal serial bus (USB) audio and video stream devices may not work if you
surprise-remove the device while the application is using the device, and then
plug the device back in.

CAUSE
=====

The USB hub driver in Windows 2000 releases bandwidth only on
IRP_MN_REMOVE_DEVICE IRP, not on IRP_MN_SURPRISE_REMOVAL.

Therefore, when a USB device is surprise-removed and if the application has a
handle to the device open, the system will not send an IRP_MN_REMOVE_DEVICE
until the handle is closed. As a result, the bandwidth is not released. If you
plug the device back in again, the device will not work because the system will
not be able to release enough bandwidth.

RESOLUTION
==========

To work around this problem, either exit the application that is using the
device, or restart the system.

Additional query words:

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Keywords          : kbDDK kbOSWin2000 kbOSWin98 kbDSupport kbUSB 
Technology        : kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000Serv kbwin2000ServSearch kbwin2000Search kbwin2000ProSearch kbwin2000Pro kbWin98search kbWinAdvServSearch kbWin98
Version           : WINDOWS:
Issue type        : kbprb

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