[Paranoia] Ripping scratched CDs: hangups

[Jonathan Morace]

On 6/14/05, Peter Jones <pjones at redhat.com> wrote:
> On Sat, 2005-05-07 at 08:38 -0600, Kim Lux wrote:
> > First of all, thanks to the authors of cdparanoia for building a great
> > utility.
> >
> > I've got a beef with cdparanoia.  It seems to hang when I rip a
> > scratched CD, even though said CD will play fine (to my ear) on the same
> > cdrom drive.  I've been using cdparanoia occasionally for 2 years on
> > different machines and all the combinations have had this problem.
> >
> > When I say hang, what happens is the Rip indicator goes to 0.2x or less
> > and the drive spins endlessly.  I can abort the rip and encode OK,
> > although that used to freeze the entire system.
> 
> So just because there wasn't a great answer posted -- if you strace the
> process, is it still going?  Or is it waiting on the device?
> 
> If it's waiting on the device, then the cd drive's firmware is probably
> trying to do error correction itself, and there's probably not a good
> way to fix it.  It might be possible if there's a setting that can be
> changed on the drive, but we'd need documentation from the manufacturer
> for that.

I've run into the cdrom drive doing error correction problem before
with my Plextor drives.  Not only would it hang the computer entirely
at times, but the drives were nowhere to be found on the SCSI bus
after triggering this problem.  I found this was being caused by SCSI
command timeouts.  I was able to increase the 5 second timeouts in the
cdparanoia code and prevent it from happening.  It will still happen
if the timeout I set is reached before the command returns, but I made
it long enough that my patience was sure to run out before the
timeout, causing me to cancel the process :).

Jonathan