Re: Read from CD-Rom -> crash

Eberhard Moenkeberg (emoenke@gwdg.de)
27 May 1996 11:21:50 GMT


Thomas Niederreiter (tn@bv.rz.fh-muenchen.de) wrote:

: there is a quite critical bug in the CD-Rom-Code which caused for me
: some extreme heavy crashes. (Reset-Button only)

This bug shows up only with SCSI CDROM drives, and it "was born"
at about 1.2.5.

: A CD-Recordable written under Linux works well, except you want to read
: the last few sectors. (e.g. when copying this CD).

Formerly, I verified my self-written CDs with SCSI drives (different
brands, mostly Toshiba); was less CPU consuming than "my own" drives.
Since abot 1.2.5, at the end of the CD the system hung. Because at
those days I didn't find time to research, I reverted to use Panasonic
and Teac drives (sbpcd), and now I'm using IDE/ATAPI drives with
success, too.

: The last 4 blocks (each 2048 bytes) can't be read in most cases.
: And here on kernel pre2.0.7 this causes the total blackout.
: 1.3.98 just reports a lot of sense-errors but recovers.

: I know that these 4 blocks are written on CD-R. (I can get the exact
: number of blocks on a CD from the ISO9660-Header).

Maybe it is simply a non-working recovery from errors during read-ahead
(into the "unformatted" section).

: I tested this only with SCSI-CD-Roms. (Don't have others)

This error does at least not exist with sbpcd and ide-cd.

Cheers -e

-- 
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