Re: cd0 errors during probe?

On Sun, Oct 12, 2003 at 14:29:38 -0700, Steve Kargl wrote:
> On Sun, Oct 12, 2003 at 02:51:50PM -0600, Kenneth D. Merry wrote:
> > On Sun, Oct 12, 2003 at 10:26:54 -0700, Steve Kargl wrote:
> > > Can I assume that the following error messages are
> > > erronous because cd0 appears to function without
> > > any problems?  There is a CD in the drive.
> > > 
> > > cd0 at ahc0 bus 0 target 4 lun 0
> > > cd0: <TOSHIBA CD-ROM XM-6401TA 1001> Removable CD-ROM SCSI-2 device 
> > > cd0: 10.000MB/s transfers (10.000MHz, offset 15)
> > > cd0: cd present [129875 x 2048 byte records]
> > > (cd0:ahc0:0:4:0): READ(10). CDB: 28 0 0 0 0 0 0 0 1 0 
> > > (cd0:ahc0:0:4:0): CAM Status: SCSI Status Error
> > > (cd0:ahc0:0:4:0): SCSI Status: Check Condition
> > > (cd0:ahc0:0:4:0): BLANK CHECK asc:64,0
> > > (cd0:ahc0:0:4:0): Illegal mode for this track
> > > (cd0:ahc0:0:4:0): Retrying Command (per Sense Data)
> > 
> > Looks like GEOM is trying to read the first sector of the CD, but since
> > it's likely an audio CD, it doesn't quite work.
> > 
> 
> Yes, it is an audio CD.  I suspected that it was a 
> transient GEOM/CAM issue, but wanted to make sure
> before I needlessly replaced the cdrom drive.

There's nothing wrong with your drive, most likely.

I suppose it plays audio CDs and reads data CDs okay?  If so, it's nothing
to worry about.

Back when the cd(4) driver used the old slice code, it had a function,
cdfirsttrackisdata(), that figured out whether the first track was an audio
or data track.  It would set the flags in the disk structure accordingly to
tell the slice code whether or not to attempt to read a disklabel from the
CD.

The code in -stable still works that way.

My guess is that we need something similar again to tell GEOM not to
attempt to read the first sector of the CD when it's not a data CD.

Ken
-- 
Kenneth Merry
ken_at_kdm.org