DOCUMENT:Q264946 28-OCT-2000 [winnt] TITLE :PRB: Bandwidth Leak of USB Device on Surprise Removal PRODUCT :Microsoft Windows NT PROD/VER:WINDOWS: OPER/SYS: KEYWORDS:kbDDK kbOSWin2000 kbOSWin98 kbDSupport kbUSB ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows 2000 Advanced Server - Microsoft Windows 2000 Server - Microsoft Windows 2000 Professional - Microsoft Windows 98 ------------------------------------------------------------------------------- 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: ====================================================================== Keywords : kbDDK kbOSWin2000 kbOSWin98 kbDSupport kbUSB Technology : kbwin2000AdvServ kbwin2000AdvServSearch kbwin2000Serv kbwin2000ServSearch kbwin2000Search kbwin2000ProSearch kbwin2000Pro kbWin98search kbWinAdvServSearch kbWin98 Version : WINDOWS: Issue type : kbprb ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2000.