From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 30 Sep 2008 16:10:27 +0100 (BST) Received: from accolon.hansenpartnership.com ([76.243.235.52]:32954 "EHLO accolon.hansenpartnership.com") by ftp.linux-mips.org with ESMTP id S29565680AbYI3PKZ (ORCPT ); Tue, 30 Sep 2008 16:10:25 +0100 Received: from localhost (localhost [127.0.0.1]) by accolon.hansenpartnership.com (Postfix) with ESMTP id 459C2856E; Tue, 30 Sep 2008 10:10:16 -0500 (CDT) Received: from accolon.hansenpartnership.com ([127.0.0.1]) by localhost (redscar.int.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Qye3tjrpgSBZ; Tue, 30 Sep 2008 10:10:14 -0500 (CDT) Received: from [153.66.150.222] (mulgrave-w.int.hansenpartnership.com [153.66.150.222]) by accolon.hansenpartnership.com (Postfix) with ESMTP id 1217F8048; Tue, 30 Sep 2008 10:10:14 -0500 (CDT) Subject: Re: [PATCH 1/2] ide: Add tx4939ide driver From: James Bottomley To: Tejun Heo Cc: Bartlomiej Zolnierkiewicz , Atsushi Nemoto , sshtylyov@ru.mvista.com, linux-mips@linux-mips.org, linux-ide@vger.kernel.org, ralf@linux-mips.org, Jens Axboe In-Reply-To: <48DEAF1F.8040200@gmail.com> References: <48C851ED.4090607@ru.mvista.com> <48CA8BEE.1090305@ru.mvista.com> <20080913.005904.07457691.anemo@mba.ocn.ne.jp> <200809271819.19510.bzolnier@gmail.com> <48DEAF1F.8040200@gmail.com> Content-Type: text/plain Date: Tue, 30 Sep 2008 10:09:47 -0500 Message-Id: <1222787387.3232.26.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 (2.22.3.1-1.fc9) Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 20667 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: James.Bottomley@HansenPartnership.com Precedence: bulk X-list: linux-mips On Sun, 2008-09-28 at 07:09 +0900, Tejun Heo wrote: > Bartlomiej Zolnierkiewicz wrote: > > On Friday 12 September 2008, Atsushi Nemoto wrote: > >> On Fri, 12 Sep 2008 19:34:06 +0400, Sergei Shtylyov wrote: > > > > [...] > > > >>>>>> + __ide_flush_dcache_range((unsigned long)addr, size); > >>>>> Why is this needed BTW? > >>>> Do you mean __ide_flush_dcache_range? This is needed to avoid cache > >>>> inconsistency on PIO drive. PIO transfer only writes to cache but > >>>> upper layers expects the data is in main memory. > >>> Hum, then I wonder why it's MIPS specific... > >> SPARC also have it. And there were some discussions for ARM IIRC. > > > > I was under the impression that it has been addressed by Tejun at > > the higher-layer level (for both ide/libata) long time ago and that > > MIPS/SPARC code are just a left-overs which could be removed now? > > cc'ing Jens and James. IIRC, I posted several patches but they never > went in. I don't remember what the objections were or whether any > alternative fix went in. Which patches were these? We have several methods of doing PIO fallback, the most common one being scatterlist.c:sg_copy_from/to_buffer() which does the cache coherency. James > Thanks. >