*BSD News Article 31436


Return to BSD News archive

Newsgroups: comp.os.386bsd.bugs
Path: sserve!newshost.anu.edu.au!munnari.oz.au!bunyip.cc.uq.oz.au!harbinger.cc.monash.edu.au!msuinfo!agate!howland.reston.ans.net!swrinde!pipex!uknet!festival!edcogsci!richard
From: richard@cogsci.ed.ac.uk (Richard Tobin)
Subject: Re: User SCSI
Message-ID: <Cqxu8q.9Bz@cogsci.ed.ac.uk>
Organization: HCRC, University of Edinburgh
References: <Cqon5K.JFC@cogsci.ed.ac.uk> <Cqvn56.AHo@tfs.com>
Date: Sun, 5 Jun 1994 19:02:49 GMT
Lines: 36

In article <Cqvn56.AHo@tfs.com> julian@tfs.com (Julian Elischer) writes:
>>Various things don't seem to work quite right, but the most serious
>>is that I can't tell how much data came from the scanner.  The
>>datalen_used field of the SCSI request does not appear to be filled
>>in correctly.

>The AHA driver doesn't use the commands that return DMA counts, becasue some
>of the early models won't work with those commands.

Aha :-)  That explains it.  I also have a problem with command timeouts:
an inquiry command returns without error even if the device is switched
off (!) rather than timing out as I would expect (on the other hand, if
a receive command just takes too long, it does time out correctly).	

>The tape drive derives it's residual counts from information sent by the 
>drive itself in the request-sense data

As far as I can tell, the ScanJet only uses the sense data to report
errors.  Incidentally, is the kernel supposed to get the sense data
itself after an error, or do I have to send a "request sense" command
myself?

>What adapter are you using?

1542CF.

>>Alternatively, does anyone have a better user-mode scsi driver?
>as I said.. peter Dufault (HD@world.std.com) has been doing some on this.

I've just got his code, and I'll be having a look at it.

-- Richard
-- 
Richard Tobin, HCRC, Edinburgh University                 R.Tobin@ed.ac.uk

"Your monkey has got it right, sir."  - HHGTTG