[PATCH] enable usb control message with class specific request

[Matthias Dellweg]

Hi!
Usb devio assumes that the wIndex in every control message apart from
those flagged as USB_TYPE_VENDOR holds the number of the Interface
being addressed. This is for example not true for the class specific
request GET_DEVICE_ID in the printer class:

"The high-byte of the wIndex field is used to specify the zero-based
interface index. The low-byte of the wIndex field is used to specify
the zero-based alternate setting." [1]

In this special case it misinterpretes the alternate setting 1 for the
interface and tries to claim a nonexisting one. Therefor you won't get
the printers name.

The patch below is a minimal approach to fix this. Maybe it should be
extended to USB_TYPE_RESERVED. Maybe there should be an extended test
that knows something about specific classes.

What do you think?
regards Matthias

[1] http://www.usb.org/developers/devclass_docs/usbprint11.pdf