Microsoft KB Archive/264946

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

Article ID: 264946

Article Last Modified on 1/27/2007

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APPLIES TO


 * Microsoft Windows 2000 Server
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Professional Edition
 * Microsoft Windows 98 Standard Edition

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This article was previously published under Q264946



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.

Keywords: kbprb kbusb KB264946

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