libusb_transfer_flags

Report short frames as errors

Automatically free() transfer buffer during libusb_free_transfer()

Automatically call libusb_free_transfer() after callback returns. * If this flag is set, it is illegal to call libusb_free_transfer() * from your transfer callback, as this will result in a double-free * when this flag is acted upon.

Terminate transfers that are a multiple of the endpoint's wMaxPacketSize with an extra zero length packet. This is useful when a device protocol mandates that each logical request is terminated by an incomplete packet (i.e. the logical requests are not separated by other means).

This flag only affects host-to-device transfers to bulk and interrupt endpoints. In other situations, it is ignored.

This flag only affects transfers with a length that is a multiple of the endpoint's wMaxPacketSize. On transfers of other lengths, this flag has no effect. Therefore, if you are working with a device that needs a ZLP whenever the end of the logical request falls on a packet boundary, then it is sensible to set this flag on <em>every</em> transfer (you do not have to worry about only setting it on transfers that end on the boundary).

This flag is currently only supported on Linux. On other systems, libusb_submit_transfer() will return LIBUSB_ERROR_NOT_SUPPORTED for every transfer where this flag is set.

Available since libusb-1.0.9.