From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: libata: Simulate REPORT LUNS for ATAPI devices when not supported Date: Mon, 04 Dec 2006 18:12:56 -0500 Message-ID: <4574AB78.40102@garzik.org> References: <4574A90E.5010801@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:39115 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967751AbWLDXM7 (ORCPT ); Mon, 4 Dec 2006 18:12:59 -0500 In-Reply-To: <4574A90E.5010801@us.ibm.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: "Darrick J. Wong" Cc: linux-scsi , Linux Kernel Mailing List , "linux-ide@vger.kernel.org" , Alan Cox Darrick J. Wong wrote: > The Quantum GoVault SATAPI removable disk device returns ATA_ERR in > response to a REPORT LUNS packet. If this happens to an ATAPI device > that is attached to a SAS controller (this is the case with sas_ata), > the device does not load because SCSI won't touch a "SCSI device" > that won't report its LUNs. If we see this command fail, we should > simulate a response that indicates the presence of LUN 0. > > Signed-off-by: Darrick J. Wong I think the answer to this issue lies in the behavior of the majority of ATAPI devices when responding to REPORT LUNS. Regardless of SAS or SATA or whatever bus the device is using. ISTR that REPORT LUNS can make ATAPI devices croak, so it might be wise and more safe to simply simulate REPORT LUNS by default for all ATAPI devices. Then readdress the issue if someone has a burning need to support the rare multi-LUN ATAPI devices. I have one, but I'm not highly motivated to dig it out. Jeff