Re: Proper way to get USB class codes

["José Félix Ontañón" <felixonta@gmail.com>]

El día 15 de enero de 2011 19:26, José Félix Ontañón
<felixonta@gmail.com> escribió:
> Hello everybody,
> I've got some doubts and problems getting USB class codes via udev and
> i'll be very grateful if someone could clarify.
>
> First of all, using udevadm i've realized some usb devices left the
> class/subclass/protocol attributes with 00:
>
>    ATTR{bDeviceClass}="00"
>    ATTR{bDeviceSubClass}="00"
>    ATTR{bDeviceProtocol}="00"
>
> Is that an issue on the usb device itself or an issue on udev reading
> usb device/interface descriptor?
>
> Second, i've some doubts about when should I use the
> ID_USB_INTERFACES, TYPE or INTERFACE property: in which cases should I
> use one or another? Why the TYPE property sometimes appear as 0/0/0
> even when the ID_USB_INTERFACES and INTERFACE properties are filled?
>
> Thanks for sharing your thoughs.

Hello everyone,

I've been doing some tests and the fact is I think this could be an
udev bug: HAL reports class/subclass/protocol for all USB devices with
no failures at all. Here the same example as above but using HAL:

  usb.interface.class = 11  (0xb)  (int)
  usb.interface.subclass = 0  (0x0)  (int)
  usb.interface.protocol = 0  (0x0)  (int)

After had been looking through bugzilla.kernel.org I realized there
weren't any bug reported about it. Does anyone think, like me, this
could be a bug? Would somebody tell me if i can perform some more
tests before reporting the bug myself?

Thanks in advance.

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