SUMMARY: Tagged command queuing

Alfredo Sola (adminsis@intelideas.com)
Wed, 26 Mar 1997 17:10:57 -0800 (PST)

Thanks to:

Casper Dik <casper@holland.Sun.COM>
Kevin.Sheehan@uniq.com.au (Kevin Sheehan)

Original problem:

I had a Quantum Fireball_TM (Fast SCSI) disk hanging from time
to time, with an error message complaining about tagged commands.

Solution:

Clearly this belonged to the tagged command queuing question of
the FAQ. However, the FAQ does not explain what the options are or how to
disable command queuing for a single drive; it just shows how to do it
for the whole system and refers to the man pages, which in turn show an
example to disable tagged queuing... And also Fast SCSI!.

Casper suggested to use scsi_options with a value of 0x378, so I
created /kernel/drv/esp.conf and added:

name="esp" parent="/iommu@0,10000000/sbus@0,10001000/espdma@4,8400000"
reg=0x4,0x8800000,0x40
target5-scsi-options=0x378;

The drive has not shown any problem since I did this and
rebooted, however I still don't know where to find out which bits in
scsi-options must be set to achieve which results (anyone knowing of a
doc regarding this is welcome to email)

Saludos,

Alfredo Sola
Administrador del sistema