WinUSB Read Problem

Tuesday, December 22, 2009

Hi All, I have decided to move forward from my implementation of BulkUSB.sys driver to using the formal implementation called WinUSB. It is a package of a kernel driver and a user-mode API documented as part of the MSDN library. When I tried to do asynchronous reads I discovered two undocumented / confusing failures: The first is GetLastError returns 997 - ERROR_IO_PENDING. This is fine for overlapped IO. The function fails and the error code means that there is more data to follow. The second is somewhat confusing: GetLastError returns 121 - ERROR_SEM_TIMEOUT "The semaphore timeout period has expired". This means that the timeout...
tags: , ,
no comments