Re: exclusive sleep mutex mskc0 (network driver) r = 0 (0xc32c3690) locked @ /usr/src/sys/dev/msk/if_msk.c:3589

On Tue, May 04, 2010 at 09:39:36AM -0400, John Baldwin wrote:
> On Monday 03 May 2010 3:55:38 pm Pyun YongHyeon wrote:
> > On Mon, May 03, 2010 at 07:01:56AM -0700, Mark Atkinson wrote:
> > > -----BEGIN PGP SIGNED MESSAGE-----
> > > Hash: SHA1
> > > 
> > > I updated to current yesterday and got the following 'witness_warn'
> > > panic upon executing 'reboot':
> > > 
> > > suspending ithread with the following locks held:
> > > exclusive sleep mutex mskc0 (network driver) r = 0 (0xc32c3690) locked _at_
> > > /usr/src/sys/dev/msk/if_msk.c:3589
> > > panic: witness_warn
> > > cpuid = 0
> > > KDB: enter: panic
> > > Physical memory: 495 MB
> > > Dumping 80 MB: 65 49 33 17 1
> > > 
> > > 
> > >    3579 static void
> > >    3580 msk_intr(void *xsc)
> > >    3581 {
> > >    3582     struct msk_softc *sc;
> > >    3583     struct msk_if_softc *sc_if0, *sc_if1;
> > >    3584     struct ifnet *ifp0, *ifp1;
> > >    3585     uint32_t status;
> > >    3586     int domore;
> > >    3587
> > >    3588     sc = xsc;
> > >    3589     MSK_LOCK(sc);
> > 
> > It seems msk(4) didn't honor IFF_DRV_RUNNING in status block update
> > check so it continued to process received packets.
> > Would you try attached patch?
> 
> Actually, this panic looks like a leaked lock.  I think this might fix it:
> 
> Index: if_msk.c
> ===================================================================
> --- if_msk.c	(revision 207329)
> +++ if_msk.c	(working copy)
> _at__at_ -3580,6 +3580,7 _at__at_
>  	    (sc->msk_pflags & MSK_FLAG_SUSPEND) != 0 ||
>  	    (status & sc->msk_intrmask) == 0) {
>  		CSR_WRITE_4(sc, B0_Y2_SP_ICR, 2);
> +		MSK_UNLOCK(sc);
>  		return;
>  	}

Nice catch! I guess I made mistake when I removed taskqueue based
interrupt handler.

Thanks!