From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH] ide/libata: fix ata_id_is_cfa() Date: Tue, 27 Jan 2009 02:53:43 +0300 Message-ID: <497E4D07.2090109@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> <497E0F76.6020606@ru.mvista.com> <20090126193550.27eef301@lxorguk.ukuu.org.uk> <497E12BC.1080809@ru.mvista.com> <20090126195430.3a8aa1ce@lxorguk.ukuu.org.uk> <497E1700.8090206@ru.mvista.com> <497E191A.1040902@pobox.com> <497E1BB8.8010408@ru.mvista.com> <20090126203319.783b0d2d@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from h155.mvista.com ([63.81.120.155]:7650 "EHLO imap.sh.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754269AbZAZXxt (ORCPT ); Mon, 26 Jan 2009 18:53:49 -0500 In-Reply-To: <20090126203319.783b0d2d@lxorguk.ukuu.org.uk> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Jeff Garzik , bzolnier@gmail.com, linux-ide@vger.kernel.org, gdu@mns.spb.ru Hello. Alan Cox wrote: >> totally wrong in that part from the very start -- CF devices don't report ATA >> standard support in word 80, that's forbidden (!) by the CF specs since at >> least 2.1. >> > > And the ATA world says that if word 80 doesn't report any standards then > the word is potentially undefined....welcome to PC hell > > Perhaps the best we can do is to test > > word 80 == 0 && word 83 bit set && word 83 valid > > Fortunately the use is almost entirely to print the right CFA/ATA string > at boot ? > There was intent to use it for filtering out DMA modes on incapable CF slots, for the lack of better criterion -- these slots usually has a master/slave switch connected, so can't be tied to the drive #, only to the channel # and the board's DMI ID. > Now Sergei if you'd said that explicitly (or if you did before I didn't > see it) it would have been a bit simpler to work out why you were arguing > the needed for these changes. > I was arguing entirely out of thinking that the version check is not really needed. The fact that CF spec. forbids reporting it was a surprise to me as well. > Alan > MBR, Sergei