[pyusb-users] Getting string descriptor

[Stefano Di M. <ste...@gm...>]

Hi anyone,
for some reason I can't get the string descriptor of an device:

# ...
    for device in devices:
        if device.iManufacturer > 0:
            string = usb.util.get_string(device, 254, device.iManufacturer)
            print "string:", string
        else:
            print "no descriptor"

My backend is the latest libusbx-1.0.14-win.

I get a similar error when I'm using C directly:

unsigned char *data = malloc(30);
ret = libusb_get_string_descriptor_ascii(handle, desc.iManufacturer, data, 29);

if (ret < 0) {
    const char *error = libusb_error_name(ret);
	printf("ERROR in retrieving string descriptor: %s\n", error);
	exit(1);
}


The error message:
"ERROR in retrieving string descriptor: LIBUSB_ERROR_NO_MEM"

Might this be a bug in libusbx?

Best regards
Stefano