From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH] minimal SAS transport class Date: Mon, 15 Aug 2005 17:21:31 +0200 Message-ID: <20050815152131.GB20854@lst.de> References: <20050815135537.GB19426@lst.de> <4300B11A.2050006@adaptec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from verein.lst.de ([213.95.11.210]:63442 "EHLO mail.lst.de") by vger.kernel.org with ESMTP id S964792AbVHOPVt (ORCPT ); Mon, 15 Aug 2005 11:21:49 -0400 Content-Disposition: inline In-Reply-To: <4300B11A.2050006@adaptec.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Luben Tuikov Cc: Christoph Hellwig , jejb@steeleye.com, ltuikov@yahoo.com, Eric.Moore@lsil.com, andrew.patterson@hp.com, linux-scsi@vger.kernel.org On Mon, Aug 15, 2005 at 11:13:30AM -0400, Luben Tuikov wrote: > > +void sas_add_target(struct sas_port *port, struct sas_identify *attached, > > + uint channel, uint target) > > +{ > > + if (attached->target_port_protocols & > > + (SAS_PROTOCOL_SSP|SAS_PROTOCOL_STP|SAS_PROTOCOL_SATA)) > > + scsi_scan_target(&port->dev, channel, target, ~0, 0, attached); > > +} > > I've a few questions: > > 1. What kind of device does the Fusion driver export? > Is this a true end device, or is this the LU in the SSP end device? > I.e. since the Fusion card firmware does everything about SAS there is, > is also LU discovery done in the firmware, or does the firmware export > only the SSP end devices and leave LU discovery to SCSI Core > (as the code suggests)? It seems to give notification for the actual LU, but doing an LU scan works if you use the target ID from those reports. Given that I prefer to do as much as possible in the transport class to have the same behaviour for different HBAs I'd prefer to not rely on the firmware's LU scan. > 2. Since I saw that (end) devices bind to ports, what is the maximum > number of ports that the Fusion firmware export? right now it reports the number of physical ports, that's four or eight for the cards I have. But again I don't have the actual documentation yet. > 3. Will control of SATA and STP devices be given to libata or will > the Fision firmware make those look like SCSI devices? Fusion makes them look like SCSI devices. As I mentioned I tested this patch only with SATA disks. But as the command translation for cards not doing thi in firmware would happen in the ->queuecommand path I don't think the transport class should be involved with it.