Re: Reproducible FreeBSD 6.0-BETA2 panic - probably ATA-ng related

Gavin Atkinson <gavin.atkinson_at_ury.york.ac.uk> wrote:

> On Sun, 21 Aug 2005, Fabian Keil wrote:
> > I own a Plextor PlexWriter Premium, the drive has a buggy firmware
> > which crashes if you try to burn multi session in SAO mode.
> > On FreeBSD 6.0-BETA2 a panic is caused:
> 
> [snip the CD ROM drive detaching...]
 
> It's a known issue.  I see exactly this same panic 80% of the time on my 
> laptop on resume from ACPI suspend.  I believe it was introduced during 
> the newbus-ification of ATA-mk3.  On the call to acd_geom_detach, 
> acd_softc is already null.
> 
> (kgdb) f 23
> #23 0xc04dd936 in acd_geom_detach (arg=0xc16dd680, flag=0)
>      at /usr/src/sys/dev/ata/atapi-cd.c:199
> 199         g_wither_geom(cdp->gp, ENXIO);
> (kgdb) list
> 194     acd_geom_detach(void *arg, int flag)
> 195     {
> 196         struct acd_softc *cdp = device_get_ivars(arg);
> 197
> 198         /* signal geom so we dont get any further requests */
> 199         g_wither_geom(cdp->gp, ENXIO);
> 200
> 201         /* fail requests on the queue and any thats "in flight" for this device */
> 202         ata_fail_requests(arg);
> 203
> (kgdb) p cdp
> $5 = (struct acd_softc *) 0x0

Thanks for the information. Is this the problem you described in
<http://lists.freebsd.org/pipermail/cvs-src/2005-May/045876.html>
and did you already find the causing commit?

Fabian
-- 
http://www.fabiankeil.de/