From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] libata: increase LBA48 max sectors to 65535 Date: Thu, 16 Feb 2006 00:04:06 +0900 Message-ID: <43F342E6.9060909@gmail.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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from pproxy.gmail.com ([64.233.166.181]:36440 "EHLO pproxy.gmail.com") by vger.kernel.org with ESMTP id S1945961AbWBOPE3 (ORCPT ); Wed, 15 Feb 2006 10:04:29 -0500 Received: by pproxy.gmail.com with SMTP id s49so1540344pyc for ; Wed, 15 Feb 2006 07:04:28 -0800 (PST) In-Reply-To: <20060215130725.GP4203@suse.de> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jens Axboe Cc: Jeff Garzik , albertcc@tw.ibm.com, linux-ide@vger.kernel.org Jens Axboe wrote: > On Wed, Feb 15 2006, Tejun Heo wrote: > >>max_hw_sectors/max_sectors separation patch made into the tree, >>increase max_sectors to its hardware limit. >> >>Signed-off-by: Tejun Heo >> >>--- >> >>Jeff, first of all, thanks for the pointer. I have two more >>questions. >> >>* I make ATA_MAX_SECTORS_LBA48 65535 (the 0000h case is supposed to be >> broken, right?); however, the comment says 65534. Should it be >> 65534? > > > Since we never noticed any breakage on !sectors on lba28, I think we can > safely assume that !sectors will work fine for lba48 as well. So why not > just make it full 64k, eg 65536? ->max_hw_sectors is an unsigned int > now, so 64k wont overflow it. > Hello, Jens. libata currently sets max_sectors to 200 (ATA_MAX_SECTORS) on lba28. Are you talking about IDE driver? IDE driver seems to set max_sectors to 256 on probe and make it 2048 while setting up ide disk if lba48. Hmmm... Can we really trust all the firmwares? I just feel that some drive out there ought have screwed up about nsect == 00h/0000h case. Thanks. -- tejun