Re: [linux-usb-devel] 2.4.10 and USB Modems...

["Michael H. Warfield" <mhw@wittsend.com>]

On Tue, Oct 02, 2001 at 07:13:11PM -0400, Pete Zaitcev wrote:
> > From: "Michael H. Warfield" <mhw@wittsend.com>
> > To: linux-kernel@vger.kernel.org, linux-usb-devel@lists.sourceforge.net
> > Cc: mhw@wittsend.com
> > Date: Tue, 2 Oct 2001 18:47:57 -0400

	[...]

> Looks like 2/2/1 had to math even with 2.4.10, but perhaps
> something is too subtle in the matching code.

> This is what Vojtech wrote me about it (I hope he forgives me
> for posting a private mail - it is a technical subject):

> > Date: Tue, 2 Oct 2001 22:36:08 +0200
> > From: Vojtech Pavlik <vojtech@suse.cz>
> > To: Pete Zaitcev <zaitcev@redhat.com>
> > Subject: Re: acm in 2.2.10

> > On Tue, Oct 02, 2001 at 02:13:00PM -0400, Pete Zaitcev wrote:
> > > This looks dubious:
> > > 
> > > --- linux-2.4.9/drivers/usb/acm.c	Wed Jul  4 20:11:17 2001
> > > +++ linux-2.4.10/drivers/usb/acm.c	Sun Sep 23 09:49:00 2001
> > > @@ -647,7 +648,8 @@
> > >   */
> > >  
> > >  static struct usb_device_id acm_ids[] = {
> > > -	{ USB_DEVICE_INFO(2, 0, 0) },
> > > +	{match_flags: (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
> > > +	bInterfaceClass: USB_CLASS_COMM, bInterfaceSubClass: 2},
> > >  	{ }
> > >  };
> > >  
> > > Are you sure there are no 2/0/0 devices out there?
> > > Someone complained about some modem on Usenet today.
> > 
> > The change wasn't by me nor blessed by me, and it's wrong. It'll be
> > reverted in following kernels. The problem is that 2/0/0 also matches
> > the CDC Ethernet class, and thus both drivers get loaded for such
> > devices via the hotplug mechanism. This works, but is slightly
> > inefficient.

	I'll confirm this.  Backing out that change (which seems to be
the only real change to acm.c) corrected the problem and the modems
are now recognized and operate under 2.4.10.

> > -- 
> > Vojtech Pavlik
> > SuSE Labs

> I think it is important to clear changes by the maintainer.
> That's what he is there for :)

	Tell me about it (I maintain the Computone multiport driver).  :-)

> -- Pete

	Mike
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