From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH 2/3] libata: extend ata_acpi_cbl_80wire() and fix cable detection in pata_via and pata_amd Date: Sat, 3 Nov 2007 02:12:08 +0100 Message-ID: <200711030212.08427.bzolnier@gmail.com> References: <472B402A.4030009@gmail.com> <20071102154215.1a93249c@the-village.bc.nu> <200711030157.00354.bzolnier@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from fk-out-0910.google.com ([209.85.128.188]:17463 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754534AbXKCBFp (ORCPT ); Fri, 2 Nov 2007 21:05:45 -0400 Received: by fk-out-0910.google.com with SMTP id z23so923645fkz for ; Fri, 02 Nov 2007 18:05:43 -0700 (PDT) In-Reply-To: <200711030157.00354.bzolnier@gmail.com> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Tejun Heo , Jeff Garzik , IDE/ATA development list On Saturday 03 November 2007, Bartlomiej Zolnierkiewicz wrote: > On Friday 02 November 2007, Alan Cox wrote: > > > Using the initial GTM value is the right thing to do because both are > > > trying to check firmware setting and by the time ->cable_detect runs > > > the controller is already forced into PIO0 by reset. > > > > As we only look at the DMA bits that doesn't matter but I agree it would > > It does matter, > > http://lkml.org/lkml/2007/10/12/537 > > " > > libata: correct handling of SRST reset sequences > > This potentially adds a regression for nVidia boxes (but ACPI cable > detection should compensate for it): > > pata_amd's ->cable_detect checks UDMA timings to get the cable type > (cable detection is done before the SRST) but pata_amd's ->set_piomode s/after/before/ of course > messes with UDMA timings. It seems that both methods need fixing. > " > > [ Now we see that since ACPI can just dump the current settings > ACPI cable detection won't help a tiny bit. ] > > AFAICS pata_via.c has the same problem w.r.t. ->set_piomode > > > be cleaner if we were more careful. Also our mode setting outside > > pata_acpi doesn't touch the ACPI settings so its ok for that reason too. > > Thanks, > Bart