Thinkpad panic woes (was Re: CDRW causes Thinkpad T41 to panic)

Daniel Eischen eischen at
Thu Jun 3 14:30:39 GMT 2004

On Thu, 3 Jun 2004, Tobias Roth wrote:

> On Tue, Jun 01, 2004 at 09:12:00PM -0400, Daniel Eischen wrote:
> > > ad0: 35293MB <HTS548040MAT00> [71707/16/63] at ata0-master UDMA100
> > > ata1-slave: FAILURE - ATAPI_IDENTIFY no interrupt
> > > ata1-slave: FAILURE - ATAPI_IDENTIFY no interrupt
> > > acd0: CDRW <UJDA755zDVD/CDRW> at ata1-master UDMA33
> > > Memory modified after free 0xc44d8a00(508) val=1ff01ff @ 0xc44d8a00
> > 
> > Has anyone figured this out yet?  Here's a traceback from my
> here are my observations: I have a T30 running -CURRENT from May 25th and
> i was able to test with two cdrw drives. one worked (almost) perfectly,
> the other one i consider broken after the results of my tests.
> i was always able to boot, never got a panic. with the broken drive, i got
> the
>   ata1-slave: FAILURE - ATAPI_IDENTIFY no interrupt
> errors others are seeing. the non-broken one did not show any errors during
> boot.

My drive is on ata1-master, not the slave.  From what I can see,
the failure for ata1-slave at boot up isn't a problem because
there is no device present on that channel.  Once booted, I was
able to use xmcd and play an audio CD on it, so it is at least
working well enough for that.  5.2.1-RELEASE doesn't show the
"ata1-slave FAILURE - ATAPI_IDENTIFY" message and booted just
fine -- there were no "Memory modified after free" messages
(and panic).  I did have to disable ACPI in order to get
5.2.1-RELEASE to work, though.

The "memory modified after free" bothers me.  It indicates
that either something is running amok with pointers, or that
references are still being made after memory is free()'d.
I've been trying to track it down, but I haven't had any
luck so far.  Anyone have any ideas on how to debug this?

Dan Eischen

More information about the freebsd-current mailing list