From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763480AbXGPNec (ORCPT ); Mon, 16 Jul 2007 09:34:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765425AbXGPNeD (ORCPT ); Mon, 16 Jul 2007 09:34:03 -0400 Received: from brick.kernel.dk ([80.160.20.94]:26705 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765348AbXGPNd7 (ORCPT ); Mon, 16 Jul 2007 09:33:59 -0400 Date: Mon, 16 Jul 2007 15:33:17 +0200 From: Jens Axboe To: Geert Uytterhoeven Cc: James Bottomley , Arnd Bergmann , linux-scsi@vger.kernel.org, Linux Kernel Development , Alessandro Rubini , Linux/PPC Development , Paul Mackerras Subject: Re: [patch 5/6] ps3: BD/DVD/CD-ROM Storage Driver Message-ID: <20070716133316.GU5195@kernel.dk> References: <1184335333.3402.20.camel@localhost.localdomain> <200707131619.54898.arnd@arndb.de> <1184340528.3402.32.camel@localhost.localdomain> <20070716121649.GI5195@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 16 2007, Geert Uytterhoeven wrote: > On Mon, 16 Jul 2007, Geert Uytterhoeven wrote: > > On Mon, 16 Jul 2007, Jens Axboe wrote: > > > On Mon, Jul 16 2007, Geert Uytterhoeven wrote: > > > > On Fri, 13 Jul 2007, Geert Uytterhoeven wrote: > > > > > Ah, that explains it. flush_dcache_page() is used in some drivers. > > > > > I'll update my patches. Thanks for the comments! > > > > > > > > Does this look OK? > > > > - Replaced KM_USER0 by KM_IRQ0 (all routines are either called from an > > > > interrupt handler, from .request_fn (ps3disk), or from .queuecommand > > > > (ps3rom)) > > > > > > That looks good. > > > > > > > - Add a call to flush_kernel_dcache_page() in routines that write to buffers > > > > > > Hmm, I would have thought a flush_dcache_page() would be more > > > appropriate, the backing could be page cache pages. > > > > OK, I'll change it to flush_dcache_page(). > > Upon closer look, while flush_kernel_dcache_page() is a no-op on ppc64, > flush_dcache_page() isn't. So I'd prefer to not call it if not really needed. > > And according to James, flush_kernel_dcache_page() should be sufficient... > > So I'm getting puzzled again... I'll let James expand on why he thinks flush_kernel_dcache_page() should be sufficient. If the backing is always user memory from get_user_pages(), then the flush_kernel_dcache_page() looks sufficient. For the normal IO paths, it could be that or page cache pages too for instance. -- Jens Axboe