From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Warning: about not setting max_sectors Date: Mon, 09 Dec 2002 08:55:41 -0600 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <200212091455.gB9Etg601956@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: (from root@localhost) by pogo.mtv1.steeleye.com (8.9.3/8.9.3) id GAA14243 for ; Mon, 9 Dec 2002 06:55:47 -0800 Received: from localhost.localdomain (sshppp-200.mtv1.steeleye.com [172.16.1.200]) by pogo.mtv1.steeleye.com (8.9.3/8.9.3) with ESMTP id GAA14154 for ; Mon, 9 Dec 2002 06:55:45 -0800 Received: from mulgrave (jejb@localhost) by localhost.localdomain (8.11.6/linuxconf) with ESMTP id gB9Etg601956 for ; Mon, 9 Dec 2002 08:55:43 -0600 List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org For some reason, the SCSI core is now warning about drivers which don't set max_sectors. Just for the record, we have two parameters in the template: sg_tablesize which determines the maximum number of scatter gather entries the host can have (corresponds to max_phys_segments in the block layer), and max_sectors, which imposes a maximum overall transfer length (corresponds to max_sectors in the block queue). The comments over max_sectors list it as optional (if unset, we set it to the scsi equivalent of machine infinity---well, actually 1024, or 512Mb for usual blocks). The reason it's unset on so many drivers is that usually, they have no absolute transfer limit, so they're just bounded by the number of entries in the scatter-gather list. I can't see a reason to force every driver suddenly to have an arbitrary max_sectors, so if no-one objects, I'll pull out the warning. James