Re: USB serial regression 2.6.31.1 -> 2.6.31.2 (and 2.6.32-rc3)

From: Alan Stern
Date: Fri Oct 09 2009 - 22:04:28 EST


On Fri, 9 Oct 2009, Alan Stern wrote:

> On Sat, 10 Oct 2009, Benjamin Herrenschmidt wrote:
>
> > (Adding Rafael)
> >
> > On Sat, 2009-10-10 at 11:31 +1100, Benjamin Herrenschmidt wrote:
> > > On Sat, 2009-10-10 at 11:25 +1100, Benjamin Herrenschmidt wrote:
> > > > Hi folks !
> > > >
> > > > My USB GSM modem (Huawei 169, pretty common stuff) stopped working in
> > > > the latest ubuntu karmic update. So far, I tracked it down to a
> > > > regression that happened in the stable releases between 2.6.31.1 and
> > > > 2.6.31.2 (still present in .3). I haven't tested 2.6.32-rc* yet and
> > > > haven't had a chance to bisect (need to make myself a trimmed
> > > > down .config first).

> This looks a lot like a hardware problem, such as bad USB cables.
> Could you collect a usbmon trace for bus 4? It ought to show whether
> this is the case or whether software is at fault.

If it's not a hardware issue and the modem really does work okay in
2.6.31.1, you should also collect a usbmon trace under that kernel for
comparison.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/