From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Jolk Subject: Re: SCSI tape (Re: scsi negotiation problem on aic79xx (39320A) in 2.6.14) Date: Mon, 27 Nov 2006 18:28:50 +0100 Message-ID: <456B2052.1060300@buf.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.buf.fr ([195.68.52.65]:425 "EHLO mail.buf.fr") by vger.kernel.org with ESMTP id S1758466AbWK0R2z (ORCPT ); Mon, 27 Nov 2006 12:28:55 -0500 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Denny Page Cc: Raymond Scholz , linux-scsi@vger.kernel.org Denny Page wrote: > The problem has to do with the speed negotiation that occurs on driver > initialization. > > That I know of, there are 2 ways to address the problem. > > For kernel 2.6.17 (and later), you can go into the Adaptec scsi bios > and explicitly limit the transfer speed for the target device to 160 MB/s. > > Alternatively, for kernel 2.6.16 (and later), you can add the following > to your boot init file: > > # Fix scsi speed negotiation on tape drive > SYS_TAPE=/sys/class/spi_transport/target0:0:3 > echo "12.5" > $SYS_TAPE/min_period > echo "1" > $SYS_TAPE/revalidate > > [Remember to change the SYS_TAPE variable to match your target device] > > You will know that you've done it correctly when you see 160MB/s as the > value of User/Goal/Curr for your target in /proc/scsi/aic79xx/*. > > In my case, it's still unclear to me whether or not the problem is the > AIC79xx, the HP LTO drive, or the scsi driver. I have successfully used your procedure in order to get an HP LTO-3 driver to work that's attached to an LSI/Fusion/MPT controller. That would seem to point to the drive or the scsi driver rather than the controller. Alex -- Alexander Jolk / BUF Compagnie tel +33-1 42 68 18 28 / fax +33-1 42 68 18 29