From owner-freebsd-scsi Wed Oct 13 8:29:28 1999 Delivered-To: freebsd-scsi@freebsd.org Received: from mail.tvol.com (mail.wgate.com [38.219.83.4]) by hub.freebsd.org (Postfix) with ESMTP id 318C814A28 for ; Wed, 13 Oct 1999 08:29:25 -0700 (PDT) (envelope-from rjesup@wgate.com) Received: from jesup.eng.tvol.net (jesup.eng.tvol.net [10.32.2.26]) by mail.tvol.com (8.8.8/8.8.3) with ESMTP id LAA09439; Wed, 13 Oct 1999 11:22:32 -0400 (EDT) Reply-To: Randell Jesup To: "Justin T. Gibbs" , Gerard Roudier , scsi@FreeBSD.ORG Subject: Re: Driver for GDT6517RD RAID controller References: <199910122345.RAA03158@caspian.plutotech.com> From: Randell Jesup Date: 13 Oct 1999 11:22:35 +0000 In-Reply-To: "Justin T. Gibbs"'s message of "Tue, 12 Oct 1999 17:45:03 -0600" Message-ID: X-Mailer: Gnus v5.6.43/Emacs 20.4 Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org "Justin T. Gibbs" writes: >In this scenario you can return BUSY status. The scenario I want to >avoid is that you have run out of controller resources to actually >tell the controller to return BUSY status. There are controllers >(like the aic7xxx chips) where having pending accept ccbs does >not consume any controller resources, but outstanding continue target >I/O or scsi I/O operations do. Really? > If you expend all of your resources >on active, but disconnected, transactions and a selection without >disconnect occurs, you are deadlocked if you can't ensure the peripheral >driver that will handle the selection has controller resources to play >with. Which resources are those? This seems very strange to me - I can't imagine what resources would be required in order to return BUSY that might not be available. Even if that's true, it sounds like a problem with the driver design. Thanks for the info though; I never would have expected that a driver might _not_ be able to return BUSY... -- Randell Jesup, Worldgate Communications, ex-Scala, ex-Amiga OS team ('88-94) rjesup@wgate.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message