Hello,
I develop a USB driver for a device with some bulk pipes and run
into a serious problem.
I use the W2K-DDK for development and test the driver with the
W2K-OS. The problem occurs after changing the MaximumTransfersize
for the bulk pipes with the USBD_PF_CHANGE_MAX_PACKET-flag set.
When I use this bulk pipes later for transfers I get an “unexpected
kernel mode exception - unhandled kernel mode trap”-blue-screen. No
further info - even in the debugger.
The bulk pipes work without problems when I don’t set the
USBD_PF_CHANGE_MAX_PACKET-flag.
The DKK-documentation says that it is necessary to set this flag to
change the MaximumTransfersize for a pipe. Does anybody know what
this flag do deep inside the USBD?
Is the MaximumTransfersize changed to my prefered size when I omit
the flag? Can the device itself cause this misbehavior? How?
Thanks for your help,
Guido