From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: What's in libata-dev.git Date: Wed, 13 Sep 2006 10:50:28 +0900 Message-ID: <450763E4.6010602@gmail.com> References: <20060911132250.GA5178@havoc.gtf.org> <45056627.7030202@ru.mvista.com> <450566A2.1090009@garzik.org> <450568F3.3020005@ru.mvista.com> <4505694D.5020304@garzik.org> <45067312.7020900@aitel.hist.no> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0102.google.com ([64.233.162.199]:55648 "EHLO nz-out-0102.google.com") by vger.kernel.org with ESMTP id S1751486AbWIMBuz (ORCPT ); Tue, 12 Sep 2006 21:50:55 -0400 Received: by nz-out-0102.google.com with SMTP id n1so864771nzf for ; Tue, 12 Sep 2006 18:50:54 -0700 (PDT) In-Reply-To: <45067312.7020900@aitel.hist.no> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Helge Hafting Cc: Linus Torvalds , Jeff Garzik , Sergei Shtylyov , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton Helge Hafting wrote: > How about a simple and harmless test? > When an IDE disk is accessed for the first time, perhaps when > the partition table is read - issue a 256-sector read and see > what happens. If it works - fine. If not, tag the thing as > supporting max 255 sectors. > > No wrecking of file systems, and full performance for > the vast majority. Before implementing anything like that, we need a test case. We don't know how a faulty drive reacts on such cases. If it actively aborts the command, we can reduce the limit to 255 sectors after upper layer issues such command, no need to do it earlier. If it times out, we can't do it during boot and it will suck later too. If it silently corrupts data (highly unlikely), we need to detect the condition during boot. I don't think it matters all that much anyway. IDE has been running w/ 256 sectors for a loooong time and someone who seeks performance from LBA28 only drive has bigger problems (also I don't think 255 would be noticeably slower than 256). -- tejun