CDC ACM composite gadget serial not working between Linux and Windows?

CDC ACM composite gadget serial not working between Linux and Windows?

[Daniel Ng]

Hi,

I've found this comment in f_acm.c, 2.6.27:

 * Note that even MS-Windows has some support for ACM.  However, that
 * support is somewhat broken because when you use ACM in a composite
 * device, having multiple interfaces confuses the poor OS.  It doesn't
 * seem to understand CDC Union descriptors.  The new "association"
 * descriptors (roughly equivalent to CDC Unions) may sometimes help.

Does this mean I will not be able to successfully connect a Linux box
to a Windows PC via the Linux box's CDC ACM composite gadget serial
driver?

Also, there are direct references to the composite driver in f_acm.c,
which tells me the following:

-In Linux (2.6.27), a CDC ACM gadget serial driver MUST be a composite
driver as well.

Is this true? If so why is such tight coupling required?

Please suggest an alternate list if this message is inappropriate for this list.

Cheers,
Daniel

Re: CDC ACM composite gadget serial not working between Linux and Windows?

[Hans-Christian Egtvedt]

On Thu, 18 Jun 2009 12:09:24 +1000
Daniel Ng <daniel.ng1234@gmail.com> wrote:

<snipp>

> Please suggest an alternate list if this message is inappropriate for
> this list.
> 

I would guess there is a lot more response to this on the linux-usb
mailing list:

http://vger.kernel.org/vger-lists.html#linux-usb

-- 
Best regards,
Hans-Christian Egtvedt