Re: 2.0 scsi BLIST_SINGLELUN and MBR-7

Edgar Toernig (
Thu, 30 Jul 1998 04:09:53 +0200

Derrick J Brashear wrote:
> I have a Nakamichi MBR-7 attached to my Sparc 4 running 2.0.35; It is detected
> as such, and I can mount CDs on all 7 luns. However, if I try to access more
> than one at once, it hangs the machine, and I must physically power-cycle it.
> So I notice BLIST_SINGLELUN, that it sets SDpnt->single_lun, and that
> ostensibly the code conditionalized on this should be excluding requests which
> are causing me headaches. Yet, from experience of about 30 minutes ago, this is
> not the case. My question is, does this code work for anyone, and I'm just
> unlucky due to setup, or does the code simply not work?

My MBR-7.4 is working fine. Two concurrent tars on 2 CDs are real slow
but cause no lock ups (2.0.32 + some patches but not scsi related).
One thing breaks the system: playing audio from one CD and trying to
access another one. It seems, that the drive has problems with
simultaneous audio playback und data access causing scsi lock ups.

There has been a bug with the BLIST_SINGLELUN (somewhere in
2.0.2x and lower). The single_lun flag was set at the wrong place and
was effectivly ignored causing an immediate lock up. Since that has been
fixed i've never got any problems with data CDs.

Ciao, ET.

PS: The dev_info entry MBR-7.4 in scsi/scsi.c is bogus. It is already
covered by the MBR-7 entry.

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