We have a problem, the issuetransfer bycontorl pipe has no return, it means the function was blocked. The functioncall such as IssueVendorTransfer.


This issue occurred sometime, not always.Debugging from USBD, we found that the we using the WAIT mode transfer, and theUSBD waitforsingleobject INFINITE.


Unlucky, we can not find the root cause,but we find a work around solution: using the NO_WAIT mode transfer and trymany times.


Because can not find the root casue, soonly using NO_WAIT mode transfer, the function will return immediately, butsome time it also reutrn FALSE. So we need to try to all this function manytimes.