uaudio attach panic: Giant not locked

[Hans Petter Selasky]

On Wednesday 05 August 2009 16:13:31 Attilio Rao wrote:
> 2009/8/5 Hans Petter Selasky <hselasky at c2i.net>:
> > On Wednesday 05 August 2009 13:43:11 Robert Watson wrote:
> >> On Wed, 5 Aug 2009, Ed Schouten wrote:
> >> > * Lucius Windschuh <lwindschuh at googlemail.com> wrote:
> >> >> So I updated my machine to CURRENT r196062 and use a USB audio
> >> >> converter. Attaching it to the machine leads to a kernel panic:
> >> >>
> >> >> <snip>
> >> >
> >> > I suspect this has something to do with the Newbus locking, which
> >> > causes some pieces of code to run without Giant held, while they
> >> > previously did.
> >>
> >> There's a patch in the re@ queue to re-add Giant around newbus
> >> attachment, per John Baldwin's request.  However, committing that patch
> >> is stalled while issues with the svn->cvs export of the new RELENG_8
> >> branch are resolved.  I expect to see the patch go into the tree RSN.
> >
> > Try this patch:
> >
> > http://perforce.freebsd.org/chv.cgi?CH=167030
>
> Hans,
> I recall of a similar problem in ukbd. I resolved it by acquiring
> Giant earlier in  ukbd_attach(), but probabilly I could just bring it
> down and pass a NULL pointer to usbd_do_transfer(), right?

Yes, correct.

I've changed the Giant mutex to a NULL one in USB P4. Maybe you can fix the 
rest?

http://perforce.freebsd.org/chv.cgi?CH=167032

--HPS