Panics and potential memory corruption when pulling out a uath device

[Weongyo Jeong]

On Tue, May 19, 2009 at 09:11:01AM +0200, Hans Petter Selasky wrote:
> On Tuesday 19 May 2009, Weongyo Jeong wrote:
> > On Tue, May 19, 2009 at 12:08:45AM +0200, Lucius Windschuh wrote:
> > > 2009/5/18 Hans Petter Selasky <hselasky at c2i.net>:
> > > > Regarding the first panic, there seems to be a detach race in both upgt
> > > > and uath, which is not USB related. Try this patch:
> > > >
> > > > http://perforce.freebsd.org/chv.cgi?CH=162250
> > >
> > > This fixes not only the first panic.
> > > I can't provoke any panic by pulling out the active device. Thanks.
> >
> > Could you please test with this patch that is slightly different with
> > Hans's patch?  It try to unsetup after stopping the device.
> >
> > If no problems I'd commit it.
> >
> > regards,
> > Weongyo Jeong
> 
> Hi,
> 
> I had added the wrong ID to the driver. Now it seems to almost work. What does 
> the following error code mean? When I run wpa_cli I see some valid scan 
> results. I have not tried to associate yet.
> 
> uath0: could not set channel, error 55
> uath0: uath_cmdsend: empty inactive queue
> uath0: could not set channel, error 55
> uath0: uath_cmdsend: empty inactive queue
> uath0: could not set channel, error 55
> uath0: uath_cmdsend: empty inactive queue
> uath0: could not set channel, error 55
> uath0: uath_cmdsend: empty inactive queue
> uath0: could not set channel, error 55
> uath0: uath_cmdsend: empty inactive queue
> uath0: could not set channel, error 55
> uath0: uath_cmdsend: empty inactive queue
> uath0: could not set channel, error 55
> uath0: uath_cmdsend: empty inactive queue
> uath0: could not set channel, error 55

It means that by some reasons the device didn't answer to the command
request the driver queued on the command queue, so all of commands are
waiting the device's responses.

regards,
Weongyo Jeong