Article ID: 904643
Article Last Modified on 2/6/2007
APPLIES TO
- Microsoft Windows CE 5.0
SYMPTOMS
Consider the following scenario. On a computer that is running Microsoft Windows CE 5.0, when you unplug a universal serial bus (USB) device that is using a bulk transfer, the memory that was allocated for the bulk transfer is not correctly freed. After you have unplugged and replugged the USB device several times in succession, the Enhance Host Controller Interface (EHCI) driver may be unable to allocate sufficient memory to enable the attachment of an additional USB device. When this occurs, the Windows CE 5.0-based computer may not recognize any subsequent USB device that you try to attach.
CAUSE
This problem is caused by a coding error in the EHCI driver that prevents the EHCI driver from correctly deallocating memory.
RESOLUTION
Software update information
A supported software update is now available from Microsoft as Windows CE 5.0 Core OS QFE 904643. To resolve this problem immediately, click the following article number for information about obtaining Windows CE Platform Builder and core operating system software updates:
837392 How to locate core operating system fixes for Microsoft Windows CE Platform Builder products
Prerequisites
This software update is supported only if all previously issued software updates for this product have also been installed.
Restart requirement
After you install this software update, you must perform a clean build of the whole platform. To clean the platform, click Clean on the Build menu. To build the platform, click Build Platform on the Build menu. You do not have to restart your computer after you apply this software update.
Software update replacement information
This software update does not replace any other software updates.
File information
The English version of this package has the file attributes (or later file attributes) that are listed in the following table.
Date Time Version Size File name -------------------------------------------------------------------------------------- 12-Sep-2005 22:13 1,379,840 Wincepb50-050912-kb904643-armv4i.msi 12-Sep-2005 22:13 1,416,704 Wincepb50-050912-kb904643-mipsii.msi 12-Sep-2005 22:13 1,417,216 Wincepb50-050912-kb904643-mipsii_fp.msi 12-Sep-2005 22:13 1,430,016 Wincepb50-050912-kb904643-mipsiv.msi 12-Sep-2005 22:13 1,430,528 Wincepb50-050912-kb904643-mipsiv_fp.msi 12-Sep-2005 22:13 1,342,976 Wincepb50-050912-kb904643-sh4.msi 12-Sep-2005 22:13 1,214,976 Wincepb50-050912-kb904643-x86.msi
The English version of this software update has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
Date Time Version Size File name ----------------------------------------------------------- Path: Public\Common\Oak\Drivers\Usb\Hcd\Usb20\Ehci 26-Jul-2005 22:45 76,491 Cpipe.cpp Path: Public\Common\Oak\Lib\Armv4i\Debug 26-Jul-2005 22:44 698,604 Ehcdmdd.lib 30-Aug-2005 23:47 1,265,710 Ehci_lib.lib Path: Public\Common\Oak\Lib\Armv4i\Retail 26-Jul-2005 22:44 428,362 Ehcdmdd.lib 30-Aug-2005 23:47 682,512 Ehci_lib.lib Path: Public\Common\Oak\Lib\Mipsii\Debug 26-Jul-2005 22:44 712,732 Ehcdmdd.lib 30-Aug-2005 23:47 1,300,248 Ehci_lib.lib Path: Public\Common\Oak\Lib\Mipsii\Retail 26-Jul-2005 22:44 410,832 Ehcdmdd.lib 30-Aug-2005 23:47 668,792 Ehci_lib.lib Path: Public\Common\Oak\Lib\Mipsii_fp\Debug 26-Jul-2005 22:44 712,788 Ehcdmdd.lib 30-Aug-2005 23:47 1,300,364 Ehci_lib.lib Path: Public\Common\Oak\Lib\Mipsii_fp\Retail 26-Jul-2005 22:44 410,898 Ehcdmdd.lib 30-Aug-2005 23:47 668,916 Ehci_lib.lib Path: Public\Common\Oak\Lib\Mipsiv\Debug 26-Jul-2005 22:45 719,310 Ehcdmdd.lib 30-Aug-2005 23:47 1,312,110 Ehci_lib.lib Path: Public\Common\Oak\Lib\Mipsiv\Retail 26-Jul-2005 22:44 411,740 Ehcdmdd.lib 30-Aug-2005 23:47 671,114 Ehci_lib.lib Path: Public\Common\Oak\Lib\Mipsiv_fp\Debug 26-Jul-2005 22:45 719,366 Ehcdmdd.lib 30-Aug-2005 23:47 1,312,226 Ehci_lib.lib Path: Public\Common\Oak\Lib\Mipsiv_fp\Retail 26-Jul-2005 22:45 411,802 Ehcdmdd.lib 30-Aug-2005 23:47 671,230 Ehci_lib.lib Path: Public\Common\Oak\Lib\Sh4\Debug 26-Jul-2005 22:44 627,710 Ehcdmdd.lib 30-Aug-2005 23:46 1,132,622 Ehci_lib.lib Path: Public\Common\Oak\Lib\Sh4\Retail 26-Jul-2005 22:43 376,966 Ehcdmdd.lib 30-Aug-2005 23:46 612,508 Ehci_lib.lib Path: Public\Common\Oak\Lib\X86\Debug 26-Jul-2005 22:43 561,102 Ehcdmdd.lib 30-Aug-2005 23:46 1,042,216 Ehci_lib.lib Path: Public\Common\Oak\Lib\X86\Retail 26-Jul-2005 22:43 364,492 Ehcdmdd.lib 30-Aug-2005 23:46 590,142 Ehci_lib.lib
WORKAROUND
To work around this problem, follow these steps to modify the %WINCEROOT%\Public\Common\Oak\Drivers\Usb\Hcd\Usb20\Ehci\Cpipe.cpp file.
- Locate and then open the %WINCEROOT%\Public\Common\Oak\Drivers\Usb\Hcd\Usb20\Ehci\Cpipe.cpp file for editing.
Locate the following lines of code:
if (m_pQueuedTransfer) { RemoveQHeadFromQueue(); m_pQueuedTransfer; m_pQueuedTransfer ->AbortTransfer(); GetQHead()->InvalidNextTD(); m_pCEhcd->AsyncBell(); Sleep(2);// this sleep is for Interrupt Pipe; m_pQueuedTransfer->DoneTransfer(); m_pQueuedTransfer = NULL; delete m_pQueuedTransfer; m_pQueuedTransfer = NULL; InsertQHeadToQueue() ; }Modify the code so that it looks similar to the following:
if (m_pQueuedTransfer) { RemoveQHeadFromQueue(); m_pQueuedTransfer ->AbortTransfer(); GetQHead()->InvalidNextTD(); m_pCEhcd->AsyncBell(); Sleep(2);// this sleep is for Interrupt Pipe; m_pQueuedTransfer->DoneTransfer(); delete m_pQueuedTransfer; m_pQueuedTransfer = NULL; InsertQHeadToQueue() ; }- Save the changes.
STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
MORE INFORMATION
When this problem occurs, the kernel debugger will contain the following message:
CPhysMem AllocateMemory : No memory available CPipe(Bulk)::IssueTransfer - no memory for TD buffer
Keywords: kbbug kbfix kbqfe kbpubtypekc KB904643
