Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262369AbTK3STu (ORCPT ); Sun, 30 Nov 2003 13:19:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262707AbTK3STu (ORCPT ); Sun, 30 Nov 2003 13:19:50 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:53428 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S262369AbTK3STg (ORCPT ); Sun, 30 Nov 2003 13:19:36 -0500 Message-ID: <3FCA34A6.3010600@pobox.com> Date: Sun, 30 Nov 2003 13:19:18 -0500 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030703 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Jens Axboe CC: Vojtech Pavlik , Bartlomiej Zolnierkiewicz , "Prakash K. Cheemplavam" , marcush@onlinehome.de, linux-kernel@vger.kernel.org, eric_mudama@Maxtor.com Subject: Re: Silicon Image 3112A SATA trouble References: <3FC36057.40108@gmx.de> <3FCA1DD3.70004@pobox.com> <20031130165146.GY10679@suse.de> <200311301758.53885.bzolnier@elka.pw.edu.pl> <3FCA2380.1050902@pobox.com> <20031130171006.GA10679@suse.de> <20031130175649.GA18670@ucw.cz> <20031130181723.GD6454@suse.de> In-Reply-To: <20031130181723.GD6454@suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jens Axboe wrote: > On Sun, Nov 30 2003, Vojtech Pavlik wrote: > >>On Sun, Nov 30, 2003 at 06:10:06PM +0100, Jens Axboe wrote: >> >> >>>On Sun, Nov 30 2003, Jeff Garzik wrote: >>> >>>>Bartlomiej Zolnierkiewicz wrote: >>>> >>>>>On Sunday 30 of November 2003 17:51, Jens Axboe wrote: >>>>> >>>>>>>Tangent: My non-pessimistic fix will involve submitting a single sector >>>>>>>DMA r/w taskfile manually, then proceeding with the remaining sectors in >>>>>>>another r/w taskfile. This doubles the interrupts on the affected >>>>>>>chipset/drive combos, but still allows large requests. I'm not terribly >>>>>> >>>>>>Or split the request 50/50. >>>>> >>>>> >>>>>We can't - hardware will lock up. >>>> >>>>Well, the constraint we must satisfy is >>>> >>>> sector_count % 15 != 1 >>> >>> (sector_count % 15 != 1) && (sector_count != 1) >>> >>>to be more precise :) >> >>I think you wanted to say: >> >> (sector_count % 15 != 1) || (sector_count == 1) > > > Ehm no, I don't think so... To my knowledge, sector_count == 1 is ok. If > not, the hardware would be seriously screwed (ok it is already) beyond > software fixups. Now that you've kicked my brain into action, yes, sector_count==1 is ok. It's all about limiting the data FIS... and with sector_count==1 there is no worry about the data FIS in this case. Jeff - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/