[lug] unreadable CDs

Andrew Gilmore agilmore at uc.usbr.gov
Wed Sep 17 09:41:04 MDT 2003

There was a comment on lkml about this, the 10 September kernel traffic
summary had it in there. Ah yes...



"Erik Andersen posted a patch and reported:

        In both 2.4 and in 2.6, error handling for bad cdrom media is
        wrong. And it is my fault I'm afraid, since I botched an earlier
        fix for the problem by putting the fix in the wrong spot.
        My kids have a "Jumpstart Toddlers" cd they have long since
        completely killed, which makes a great test disc. Without this
        fix, the best time projection I can get for completing a dd type
        sector copy is about 2 years... Most of that is spent thrashing
        about in kernel space trying to re-read sectors we already know
        are not correctable.... After the fix, I was able to rip a copy
        the CD (or rather muddle through it getting lots of EIO errors)
        in about 15 minutes.

I would expect Redhat to eventually get this into their kernel, if you
want to wait. Otherwise, you could try this yourself, or...?

Good luck, I've seen the same problem.


On Wed, 2003-09-17 at 09:30, Steve Sullivan wrote:
> Hi,
> When I try to read a bogus CD on my Redhat 9 laptop it goes
> into a long error recovery loop, retrying the bad sector.
> Meanwhile the rest of the system is essentially frozen.
> This takes about 10 minutes.  Is there any way to
> instruct the driver, or whatever, to try once or twice
> and then give up instead of all the retries?
> Many thanks,
> Steve
> ========================================
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