I asked about this before in here and got some good hints. I still
can't mount cdr's I've written on my Inspiron 8600 laptop with the NEC
ND-5100a CD/DVD+RW. The symptom is that CDRs won't mount and the output
to /var/log/messages says the disk is timing out:
kernel: hdc: irq timeout: status=0xd0 { Busy }
kernel: hdc: irq timeout: error=0xd0LastFailedSense 0x0d
kernel: hdc: DMA disabled
kernel: hdc: ATAPI reset complete
I've been reading everywhere about cdrom/dvd problems in linux. I note
that this error has been observed now and then since 1998, and there's
never a very good explanation of what's wrong. Some people suspect
hardware failure. I have made bug reports, first to the redhat bugzilla:
http://bugzilla.kernel.org/show_bug.cgi?id=3755
And then last night to the kernel.org itself.
http://bugzilla.kernel.org/show_bug.cgi?id=3755
The important new information is that when starting with no kernel
option or with hdc=ide-cd, I CAN mount cdrom's printed at the factory
(Microsoft, for example), but cannot mount CDRs that I write. I found
at least one bug reporter who contended that the way Fedora core 2
writes the "last part" of a CDR is not managed well by the ide-cd
module. On the other hand, ide-scsi can mount either kind of disk.
Before I found that ide-scsi would cause disks to be mounted, I was
thinking the problem was in the CD-DVD+RW device itself. People have
contended to me that when you lose the ability to read CDRs, it is a
signal that your laser is getting weak, because the CDRs you make
yourself are not so sharp and clear as the one the factory makes with
its high quality writers. There may still be some truth in that, but I
think that if it really was the cause of trouble, then setting
hdc=ide-scsi would not help.
It seems to me the problem has to be in the ide-cd support. This bug
report on kernel.org suggests as much, but I do not know if the author
is correct or not:
http://bugzilla.kernel.org/show_bug.cgi?id=3362
Here's what I don't understand: If there is some bug in CD reading, why
doesn't it affect all Linux systems. Why just a few of us?
--
Paul E. Johnson email: pauljohn@xxxxxx
Dept. of Political Science http://lark.cc.ku.edu/~pauljohn
1541 Lilac Lane, Rm 504
University of Kansas Office: (785) 864-9086
Lawrence, Kansas 66044-3177 FAX: (785) 864-5700