From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 09 Sep 2010 19:37:07 +0200 (CEST) Received: from elvis.franken.de ([193.175.24.41]:37112 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1491101Ab0IIRhE (ORCPT ); Thu, 9 Sep 2010 19:37:04 +0200 Received: from uucp (helo=solo.franken.de) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1Otl3X-000126-00; Thu, 09 Sep 2010 19:37:03 +0200 Received: by solo.franken.de (Postfix, from userid 1000) id 17ADB2397F0; Thu, 9 Sep 2010 19:34:27 +0200 (CEST) Date: Thu, 9 Sep 2010 19:34:27 +0200 From: Thomas Bogendoerfer To: David Daney Cc: Kevin Cernekee , Ralf Baechle , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] MIPS: DMA: Add plat_extra_sync_for_cpu() Message-ID: <20100909173426.GA14371@alpha.franken.de> References: <064bb0722da5d8c271c2bd9fe0a521cc@localhost> <99a0868bdbcfa8785a92b4af4f6d9b99@localhost> <4C8914E8.5030002@caviumnetworks.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C8914E8.5030002@caviumnetworks.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-archive-position: 27740 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: tsbogend@alpha.franken.de Precedence: bulk X-list: linux-mips Return-Path: X-Keywords: X-UID: 7443 On Thu, Sep 09, 2010 at 10:10:00AM -0700, David Daney wrote: > On 09/08/2010 04:02 PM, Kevin Cernekee wrote: >> On noncoherent processors with a readahead cache, an extra platform- >> specific invalidation is required during the dma_sync_*_for_cpu() >> operations to keep drivers from seeing stale prefetched data. > > But as far as I can see, none of your plat_extra_sync_for_cpu() do anything. > > Perhaps adding this hook should be deferred until there is actually a user. looks like this is doing what the non_coherent_r10000 case does. So IMHO either which make non_coheren check more generic or could use the new plat_sync thingie for IP28 and other non coherent r10k boxes. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessary a good idea. [ RFC1925, 2.3 ]