[Libusb-devel] Timeouts in transfers

[Bas v. D. <v.d...@gm...>]

Hello,

I'm the author of the high-level Haskell binding[1] for libusb-1.0. I
have a question regarding timeouts in transfers:

The documentation for 'libusb_bulk_transfer' and
'libusb_interrupt_transfer' states:

"...Also check transferred when dealing with a timeout error code.
libusb may have to split your transfer into a number of chunks to
satisfy underlying O/S requirements, meaning that the timeout may
expire after the first few chunks have completed. libusb is careful
not to lose any data that may have been transferred; do not assume
that timeout conditions indicate a complete lack of I/O..."

Does this apply to both reads and writes? So if I do a bulk read and a
timeout occurs can I still expect 'transferred' number of bytes in my
data buffer. And if I do a bulk write and a timeout occurs can I still
expect that 'transferred' number of bytes have been written?

And does this also apply to control transfers?

Thanks,

Bas van Dijk

[1] http://hackage.haskell.org/package/usb