Hi all,
I just found an ugly bug and a fatal bug in Linux 2.4.2-4GB:
- The ugly bug is that the sg driver in ioctl() mode
does not set the SCSI status byte correctly (at least
when the drive is ATAPI).
Note that ATAPI has no SCSI status byte but there is
a IDE status bit that is used to signal the driver to
fetch sense data. This bit is equivalent to CHECK_CONDITION
in the SCSI status byte. So a conforming SCSI driver needs
to emulate the CHECK_CONDITION bit (0x02) in the SCSI
status byte in this case.
Observed behaviour (with cdrecord -d):
ioctl ret: 0
host_status: 00 driver_status: 28
cdrecord: Input/output error. read toc: scsi sendcmd: no error
CDB: 43 00 00 00 00 00 00 00 04 00
status: 0x0 (GOOD STATUS)
cmd finished after 0.000s timeout 40s
The driver status includes DID_SENSE but the SCSI status is 0!
This causes cdrecord not wo work properly in all cases - please fix
as soon as possible.
Check/Repeat with the scgcheck program!
- The fatal bug is that Linux 2.4.2-4GB dies on a
DMA overrun situation.
My observed behaviour was that the machine freezes and
a ping from another machine is not answered anymore.
Check/Repeat with the scgcheck program!
BTW: scgcheck is now out for one month. It seems to be a good idea
to for correct check kernel behaviour in error situations
from time to time.
Note that incorrect behaviour for error situatiuons in the
Linux sg driver was the most frequent problem in the past.
Jörg
EMail:[EMAIL PROTECTED] (home) Jörg Schilling D-13353 Berlin
[EMAIL PROTECTED] (uni) If you don't have iso-8859-1
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URL: http://www.fokus.gmd.de/usr/schilling ftp://ftp.fokus.gmd.de/pub/unix
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