From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: [PATCH] libata: increase LBA48 max sectors to 65535 Date: Mon, 20 Feb 2006 08:54:24 -0500 Message-ID: <43F9CA10.8000206@pobox.com> References: <1139754779159-git-send-email-htejun@gmail.com> <43EF8E61.5040409@pobox.com> <43EFD73D.4070207@gmail.com> <43F011DF.6020203@pobox.com> <20060215072449.GA31691@htj.dyndns.org> <20060215130725.GP4203@suse.de> <43F342E6.9060909@gmail.com> <20060215151200.GW4203@suse.de> <43F38D49.4080601@pobox.com> <43F3B3CE.5060105@pobox.com> <43F9A6A8.4020606@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mx3.magma.ca ([206.191.0.239]:42451 "EHLO mx3.magma.ca") by vger.kernel.org with ESMTP id S1030229AbWBTNyh (ORCPT ); Mon, 20 Feb 2006 08:54:37 -0500 In-Reply-To: <43F9A6A8.4020606@pobox.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: Jens Axboe , Tejun Heo , albertcc@tw.ibm.com, linux-ide@vger.kernel.org Jeff Garzik wrote: > > Indeed. I am paranoid about controllers assuming that no more than 256 > PRD entries will be submitted. But I have never seen any document that > says PCI IDE BMDMA hardware can -only- do 256 PRD entries. Never tested > it, either... The hardware vendors I have worked with have never had any limit on PRD count -- they'd happily keep reading through an infinite list of PRDs if we could supply one. A number of them did have issues with 64KB boundary crossings, and it is generally VERY unsafe to have a single PRD "wrap" into a fresh 64KB segment mid-stride. Cheers -- Mark Lord Real-Time Remedies Inc. mlord@pobox.com