Bug 14819

Summary: REQ: support for ``immediate'' SCSI commands
Product: Base System Reporter: ab <ab>
Component: kernAssignee: freebsd-bugs (Nobody) <bugs>
Status: Closed FIXED    
Severity: Affects Only Me    
Priority: Normal    
Version: Unspecified   
Hardware: Any   
OS: Any   

Description ab 1999-11-11 06:10:00 UTC 
The OnStream SC50 tape drive doesn't work with mt(1), which prints the
following error and exits for all commands:

	mt: /dev/nrsa0: Invalid argument

And the following dmesg is logged simultaneously:

	(sa0:ahc0:0:6:0): REWIND. CDB: 1 0 0 0 0 0 
	(sa0:ahc0:0:6:0): ILLEGAL REQUEST info?:b6ca6 asc:24,0
	(sa0:ahc0:0:6:0): Invalid field in CDB

After some experiment, it seems that the drive only accepts REWIND
command only when the `immediate' flag is set in CDB, i.e. `camcontrol
cmd -c 1 1 0 0 0 0 -n sa' works as expected.

Fix: 

No fix or workaround known.
How-To-Repeat: Install the OnStream SC50 tape drive and issue `mt status'.
Comment 1 Matt Jacob freebsd_committer freebsd_triage 1999-11-11 07:13:03 UTC 
State Changed
From-To: open->closed

rejected: We will *not* blanket support immediate mode commands in the tape 
driver or any other drivedr. It's a sure way to get a jammed SCSI bus. 
It's only broken h/w like the OnStream that require it.