From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH] ide: Fix ata_id_has_dword_io to return DWORD I/O support properly Date: Fri, 19 Dec 2008 00:13:09 +0100 Message-ID: <200812190013.10156.bzolnier@gmail.com> References: <494A5BBF.8000807@inf.tu-dresden.de> <200812182142.16533.bzolnier@gmail.com> <20081218224010.45e3ce55@lxorguk.ukuu.org.uk> 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 ([209.85.128.184]:5649 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753570AbYLRXOU (ORCPT ); Thu, 18 Dec 2008 18:14:20 -0500 In-Reply-To: <20081218224010.45e3ce55@lxorguk.ukuu.org.uk> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cox Cc: Sergei Shtylyov , Jeff Garzik , Mario Schwalbe , linux-kernel@vger.kernel.org, Linux IDE mailing list On Thursday 18 December 2008, Alan Cox wrote: > > OTOH the current patch is safe even for 2.6.28 (based on years of experience > > with the check that we had in IDE subsystem) and will fix some libata drivers > > (pata_legacy, pata_qdi and pata_winbond) to use dword IO on >= ATA-2 devices. > > > > [ In reality this a regression fix for IDE -> libata conversion as it is a > > huge performance improvement for the above mentioned DMA-less drivers. ] > > The 32bit PIO support is already queued up and went to Jeff a while ago > so thats all in hand - its btw a big win on some suprising chipset cases > including Intel ICH chipsets. It is a not exactly the same issue as the pata_{legacy,qdi,winbond} one discussed above. Anyway cool to see another IDE -> libata regression fixed. > > Jeff, I would like to merge it through IDE tree since the other patch depends > > on it but if you want to go ahead and push it to Linus earlier feel free to > > do it (or I can include it into the next IDE fixes pull request if you like). > > Its still broken. You cannot use the version check for versions below 3. Hmm, this doesn't seem to be a problem w.r.t. to the patch we are discussing because in such case ata_id_major_version() will just return 0 and the check will behave in the identical way as it was before the patch. > I remain unconvinced we should be looking at it anywhere except specific > pure ISA cycle pass through hardware and thus it belongs as a helper for > those drivers not as ata_has_mumble stuff as its not ATA - eide_* maybe. Sure, we can always improve things further later. However Mario's patch is _definitely_ an improvement over the _current_ code. Don't you agree? [ There are no alternative patches to consider currently so... ] Thanks, Bart