Date: Thu, 06 Feb 1997 11:10:41 -0800 (PST) From: Simon Shapiro <Shimon@i-Connect.Net> To: Peter Dufault <dufault@hda.com> Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: Some SCSI Questions... Message-ID: <XFMail.970206131700.Shimon@i-Connect.Net> In-Reply-To: <199702052321.SAA01744@hda.hda.com>
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Hi Peter Dufault; On 05-Feb-97 you wrote: ... > > a. What is the /dev entry? > > The .ctl entry, e.g., /dev/rcd0a.ctl Ah! Almost Plan9 :-) > > b. What options in config do I need to turn on? > None. Good! No mistakes possible here :-) > > c. (At least) header file pathname to API > > sys/scsiio.h and scsi.h for the library. Try "man 3 scsi" and "man 8 scsi". Aha! This is where they went. Thanx. > Also, I'm sending a new test release under separate mail for your input. > > I don't know how well developed the reset code is. I'd expect > that an xs will target a given bus. The "scsiop" escapes were > in there to support, e.g., resetting a specific device versus > the bus. See the aha code. Probably Justin has to explain it from here. A device is not my problem. The code i have seen appears to synonym an HBA with its bus, and reset both. Even the Adaptec 39xx are really a single bus device, so resetting one resets the other. I am dealing with an HBA that has three distinct busses on the same controller. When and if a reset is necessary, I need a way to know what to reset: The HBA itself or its SCSI busses (which one?). These are not the same. consider an HBA with 3 SCSI wide busses, each having only 15 devices. Now, a SCSI_RESET command comes from above (why?). Say why = bus timeout (the easiest case). Do I reset the HBA, taking down 30 disk drives that have no problem, along with several hundreds of queued commands? Just trying to detangle the queued, tagged, in-driver queued, etc. commands will make you grey in the head quickly. Now, add to this a multi-initiator, where each SCSI bus has at least TWO HBA's on it. each running from a separate host, maybe not FreeBSD on the other side. Maybe NT. We don't know. This is why I am trying to understand the reset policy. The question of differentiating driver/HBA/bus/device reset is just an opener, to get me somewhat familiar with the surroundings. Once we solve this problem, we will have a very interesting set of I/O capabilities. Thanx for all your patience... Simon
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