From owner-freebsd-current@FreeBSD.ORG Thu Nov 11 10:33:07 2010 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8A99E10656A8 for ; Thu, 11 Nov 2010 10:33:07 +0000 (UTC) (envelope-from joerg.schilling9ab33xy531fokus.fraunhofer.de@bounce.antispameurope.com) Received: from relay01-haj2.antispameurope.com (relay01-haj2.antispameurope.com [83.246.65.51]) by mx1.freebsd.org (Postfix) with ESMTP id 16CF58FC1F for ; Thu, 11 Nov 2010 10:33:06 +0000 (UTC) Received: by relay01-haj2.antispameurope.com (ASE-Secure-MTA, from userid 1000) id B40C01600D4; Thu, 11 Nov 2010 11:33:04 +0100 (CET) Received: from pluto.fokus.fraunhofer.de (pluto.fokus.fraunhofer.de [195.37.77.164]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by relay01-haj2.antispameurope.com (ASE-Secure-MTA) with ESMTP id 31E5B1600B1; Thu, 11 Nov 2010 11:33:03 +0100 (CET) Received: from EXCHSRV.fokus.fraunhofer.de (bohr.fokus.fraunhofer.de [10.147.9.231]) by pluto.fokus.fraunhofer.de (8.14.2/8.14.2) with SMTP id oABAX3S6001742; Thu, 11 Nov 2010 11:33:03 +0100 (MET) Received: from rigel ([10.147.65.195]) by EXCHSRV.fokus.fraunhofer.de with Microsoft SMTPSVC(6.0.3790.3959); Thu, 11 Nov 2010 11:33:04 +0100 Date: Thu, 11 Nov 2010 11:33:03 +0100 From: Joerg.Schilling@fokus.fraunhofer.de (Joerg Schilling) To: mav@FreeBSD.org Message-ID: <4cdbc65f.bo+mYNFB2GPwXmq7%Joerg.Schilling@fokus.fraunhofer.de> References: <4CD45209.5010607@FreeBSD.org> <20101105192028.GA68728@alchemy.franken.de> <4cd822df.o/wBtwsNCXiy8xZn%Joerg.Schilling@fokus.fraunhofer.de> <4CD82E2A.3070407@FreeBSD.org> <4cd8320a.U7/OjtLLBVtE4dTy%Joerg.Schilling@fokus.fraunhofer.de> <4CD83535.1010008@FreeBSD.org> <4cdbbfef.v4cr/k2jZr9gdpyF%Joerg.Schilling@fokus.fraunhofer.de> <4CDBC55B.1040307@FreeBSD.org> In-Reply-To: <4CDBC55B.1040307@FreeBSD.org> User-Agent: nail 11.22 3/20/05 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-OriginalArrivalTime: 11 Nov 2010 10:33:04.0173 (UTC) FILETIME=[D27855D0:01CB818B] X-Mailman-Approved-At: Thu, 11 Nov 2010 12:00:33 +0000 Cc: freebsd-scsi@FreeBSD.org, freebsd-current@FreeBSD.org, freebsd-stable@FreeBSD.org, marius@alchemy.franken.de Subject: Re: Sense fetching [Was: cdrtools /devel ...] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Nov 2010 10:33:07 -0000 Alexander Motin wrote: > > The question still remains whether the previous implementation did return resid > >> 0 in some cases. In this case, I would need to implement both variants in the > > libscg adaption layer and I would need to know whether I am running on an old > > version or on a new version kernel. Do you know of a simple method to implement > > this distinction? > > Yes, some drivers were permanently reporting zero resid, while others > (mostly real SCSI) were reporting proper values. Now it is the same, > just more cases should work properly. > > Why do you want/need to distinguish them? You should already handle > non-zero resid properly. Zero resid may be wrong in some cases, but at > first I don't see fatal problem from it and at second I don't see what > can you do about it. > > If I am missing something - sorry, explain it to me please. Compare the number of sense bytes I like to request (18) with the number previous FreeBSD versions did actually request. It is obvious that in case there is a resid reported onm an old kernel, libscg (with your chanhge) would believe that probably less that the absolute minumum of sense data is available. Jörg -- EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin js@cs.tu-berlin.de (uni) joerg.schilling@fokus.fraunhofer.de (work) Blog: http://schily.blogspot.com/ URL: http://cdrecord.berlios.de/private/ ftp://ftp.berlios.de/pub/schily