From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] ide/libata: fix ata_id_is_cfa() Date: Mon, 26 Jan 2009 23:59:24 +0300 Message-ID: <497E242C.3040307@ru.mvista.com> References: <200901231615.38011.sshtylyov@ru.mvista.com> <497B9EE4.8010807@ru.mvista.com> <497E0548.80904@ru.mvista.com> <20090126190801.7d198246@lxorguk.ukuu.org.uk> <497E0EF3.2000201@ru.mvista.com> <497E101C.9040008@ru.mvista.com> <20090126194237.4897b6ce@lxorguk.ukuu.org.uk> <497E1550.1000501@ru.mvista.com> <20090126200143.733b0cec@lxorguk.ukuu.org.uk> <497E1DBB.80709@ru.mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from h155.mvista.com ([63.81.120.155]:5114 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751470AbZAZU6y (ORCPT ); Mon, 26 Jan 2009 15:58:54 -0500 In-Reply-To: <497E1DBB.80709@ru.mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: bzolnier@gmail.com, jgarzik@pobox.com, linux-ide@vger.kernel.org, gdu@mns.spb.ru Hello, I wrote: >> I shall draw the obvious conclusion from the fact you don't feel like >> providing one >> The logic is this >> ATA-3 or higher - that word has a defined meaning >> ATA < 3 that word should be 0x0000 >> pre ATA (EIDE) or head up backside implementations that would will be >> anything but usually 0x0000 or 0xFFFF >> We cannot test for ATA < 3 because there is no version bit for it > That's not quite true, read the ATA-3 standard better. >> Therefore we want to check >> CFA signature -> CFA (good for CFA 1.1 and later devices using it) >> ATA >= 3 claimed - word is trustable bit is 0 or means CFA > The problem is that the CF specs explicitly forbid (!) to report > anything in word 80 -- it's reserved and must be 0. > >> Yes the implementation is paranoid, but having done ten years working for >> a distro dealing with PC hardware in volume day in and day out I've yet > Working while checking word 82 ISO word 83? Who are you trying to cheat? I'm sorry, that was totally off base. I've misread this whole paragraph in haste. :-< The rest of my evening was wasted, sigh. MBR, Sergei