diff --git a/libusb/os/darwin_usb.c b/libusb/os/darwin_usb.c index b0ee5b2..fe40899 100644 --- a/libusb/os/darwin_usb.c +++ b/libusb/os/darwin_usb.c @@ -1449,8 +1449,14 @@ static int submit_bulk_transfer(struct usbi_transfer *itransfer) { cInterface = &priv->interfaces[iface]; - (*(cInterface->interface))->GetPipeProperties (cInterface->interface, pipeRef, &direction, &number, - &transferType, &maxPacketSize, &interval); + ret = (*(cInterface->interface))->GetPipeProperties (cInterface->interface, pipeRef, &direction, &number, + &transferType, &maxPacketSize, &interval); + + if (ret) { + usbi_err (TRANSFER_CTX (transfer), "bulk transfer failed (dir = %s): %s (code = 0x%08x)", IS_XFERIN(transfer) ? "In" : "Out", + darwin_error_str(ret), ret); + return darwin_to_libusb (ret); + } if (0 != (transfer->length % maxPacketSize)) { /* do not need a zero packet */