Subject: Re: Multi tech MTA128ST-USB (USB ISDN terminal adapter)
To: Peter Burnett <peterbu@bemac.com>
From: Brad du Plessis <bradd@cat.co.za>
List: netbsd-help
Date: 03/08/2004 12:28:33
I found the same problem with this device and put in quite a nasty hack (=
the=20
same as what you did I think) to get it to work. I was surprised that aft=
er=20
hacking the code that it worked at all. It works in windoze without a=20
problem.

Unfortunately USB ISDN terminal adapters that work under NetBSD seem to b=
e=20
quite rare.

Brad

On Monday 08 March 2004 12:26, Peter Burnett wrote:
> Hi,
>
> I've discovered a problem with this device. Wonder if anyone can shed s=
ome
> light.
>
> It conforms to the CDC ACM so should work with the umodem driver but
> initially I got a device error.
>
> What was happening was this:
> 1. USB driver reads first eight bytes of device descriptor and sees
> maxpacket size of 64
> 2. Sets maxpacket size of 64 in default control pipe endpoint and tries=
 to
> read full device descriptor (18 bytes)
> 3. This gives an UNDERRUN presumably because the data is coming back in=
 8
> byte packets still.
> Hence the device error.
>
> I did a hack so that it sets the max packet size after reading the full
> device descriptor and now it works fine.
>
> However I'm concerned because I've read section 5.5.3 of the USB spec a=
nd
> it seems to me that the code was right in the first place and the devic=
e
> was behaving wrongly.
>
> Any ideas?
>
> Peter Burnett
> peterbu@bemac.com