From owner-freebsd-scsi Wed Sep 30 13:03:08 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA10891 for freebsd-scsi-outgoing; Wed, 30 Sep 1998 13:03:08 -0700 (PDT) (envelope-from owner-freebsd-scsi@FreeBSD.ORG) Received: from pluto.plutotech.com (mail.plutotech.com [206.168.67.137]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id NAA10871 for ; Wed, 30 Sep 1998 13:03:02 -0700 (PDT) (envelope-from gibbs@plutotech.com) Received: from narnia.plutotech.com (narnia.plutotech.com [206.168.67.130]) by pluto.plutotech.com (8.8.7/8.8.5) with ESMTP id OAA22127; Wed, 30 Sep 1998 14:02:41 -0600 (MDT) Message-Id: <199809302002.OAA22127@pluto.plutotech.com> X-Mailer: exmh version 2.0.2 2/24/98 To: torstenb@vmunix.org (Torsten Blum) cc: gibbs@plutotech.com (Justin T. Gibbs), scsi@FreeBSD.ORG Subject: Re: Command Linking In-reply-to: Your message of "Wed, 30 Sep 1998 21:32:03 +0200." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 30 Sep 1998 13:56:10 -0600 From: "Justin T. Gibbs" Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >> Do you have to load the firmware using a series of linked commands >> instead of unlinked commands? > >Yes, the alternative is one write buffer for the whole firmware image, >which doesnt work due to the 64k physio limitation. We need to make that limitation go away. >> I had no intention of supporting this feature in the aic7xxx driver > >Hm, why ? Because very few, mostly older, devices support it. It doesn't provide any performance benefit if you have a modern controller and device (i.e. any that controller FreeBSD supports and a tape drive with a minimal write buffer). It can also unfairly lock out other devices from using the SCSI bus for long periods of time. None of our peripheral drivers make use of this feature. Adding support into the firmware of the aic7xxx driver is a space issue, but probably possible. Does the drive support loading firmware from tape? > -tb -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message