Date: Mon, 4 Mar 2002 22:42:34 -0800 From: Carl Reisinger <cer@mirapoint.com> To: "Kenneth D. Merry" <ken@kdm.org> Cc: Carl Reisinger <cer@mirapoint.com>, freebsd-scsi@FreeBSD.ORG Subject: Re: Writing > 64KB records to SCSI Tape, FreeBSD 4.1 (?) Message-ID: <200203050641.AOD06786@mail.mirapoint.com>
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>I believe that's pretty close to what an Adaptec 1542 can handle, so that's >why we've left it at that size. (From a CAM standpoint that is.) I haven't laid hands or eyes on a 1542 in nearly 8 years. But from watching this list it seems a fair number of people have cards that I haven't seen in years. > >I would suggest just bumping si_iosize_max up to 128K in your copy of the >sa(4) driver and see if that does the trick. > That's what I would like to do, but my knowledge of the sa driver, and FreeBSD drivers in general, is slim. Since sending my original message I have spent more time looking over the code. If I understand things correctly the dev parameter to saopen is actually a pointer to a specinfo structure and I can just change the value of si_iosize_max in saopen. True? If I want to get real fancy I can set si_iosize_max in samount after the max record size supported by the drive is found. (use the min of MAXPHYS and the drive max) (Now if there was a way to query the HBA for its max transfer size). The good news, for me, is that the controllers I need to support is very limited. aic7899 and a few Symbios controllers. The aic7899 seems to handle 16MB transfers. Don't know about the Symbios chips. >> NOTE: While most of the kernel is based on 4.1-STABLE, I >> believe the CAM subsystem and scsi_sa has been lifted from >> 4.3. (The behaviour is the same under 4.5) > >Sounds "interesting". :) > We try to limit "changes", but every so often we need a fix from a later release. And sometimes that involves back porting a fair amount of code. I forget what the 4.1 CAM problem was that caused us to pull in the 4.3 code. Carl To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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