Table of Contents
1. OPENBSD UGEN PERFORMANCE
VERY SLOW
1.1. USBHS TEST:
USE THIS TOOL TEST: https://github.com/ataradov/usb-sniffer
$ ./usb_sniffer --test Transfer rate: 7.98 MB/s Transfer rate: 7.97 MB/s Transfer rate: 7.98 MB/s Transfer rate: 7.98 MB/s Transfer rate: 7.98 MB/s Transfer rate: 7.97 MB/s Transfer rate: 7.97 MB/s Transfer rate: 7.98 MB/s Transfer rate: 7.98 MB/s Transfer rate: 7.97 MB/s Transfer rate: 7.98 MB/s Transfer rate: 7.98 MB/s
1.2. WHY
libusb/libusb/os/openbsdusb.c:688
if (IS_XFERIN(transfer)) {
if ((transfer->flags & LIBUSB_TRANSFER_SHORT_NOT_OK) == 0)
if (ioctl(fd, USB_SET_SHORT_XFER, &nr) < 0)
return _errno_to_libusb(errno);
nr = read(fd, transfer->buffer, transfer->length);
} else {
nr = write(fd, transfer->buffer, transfer->length);
}
NOT SUPPORT LINUX URB STYLE QUEUE