Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753139AbZKQNuM (ORCPT ); Tue, 17 Nov 2009 08:50:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752408AbZKQNuL (ORCPT ); Tue, 17 Nov 2009 08:50:11 -0500 Received: from eddie.linux-mips.org ([78.24.191.182]:43041 "EHLO eddie.linux-mips.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751708AbZKQNuK (ORCPT ); Tue, 17 Nov 2009 08:50:10 -0500 Date: Tue, 17 Nov 2009 14:50:03 +0100 From: Ralf Baechle To: Takashi Iwai Cc: Wu Zhangjin , Jaroslav Kysela , alsa-devel@alsa-project.org, linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Wu Zhangjin Subject: Re: [PATCH] MIPS: Fixups of ALSA memory maps Message-ID: <20091117135003.GB27085@linux-mips.org> References: <9cbcd06037c18288a6493459b8f3a6e1562eca77.1258389992.git.wuzhangjin@gmail.com> <20091116170641.GD14948@linux-mips.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2040 Lines: 52 On Mon, Nov 16, 2009 at 06:14:14PM +0100, Takashi Iwai wrote: > > > Seems this is MIPS specific, but it's not that easy to move this patch > > > into the arch/mips part, So, any better solution? > > > > > > Thanks & Regards, > > > Wu Zhangjin > > > > > > ------------------------ > > > > > > The user application mmap audio dma regions must be dma-coherent. This > > > patch fix it. > > > > > > Without this patch, artsd will fail on boot, and mplayer will exit with > > > "Segmentation fault". (this happens on YeeLoong netbook, fuloong2f > > > mini pc with snd_cs5535 audio card) > > > > > > This is originally from the to-mips branch of > > > http://dev.lemote.com/code/linux_loongson, and contributed by Yanhua > > > from Lemote Inc. > > > > > > Reported-by: qiaochong > > > Signed-off-by: Wu Zhangjin > > > > This issue is an old ghost still around, see: > > > > http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=20060124.132832.37533152.nemoto%40toshiba-tops.co.jp > > > > which is a superset of your proposed patch and which itself is refering to > > an even older posting from 2003: > > > > http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=20030523215935.71373.qmail%40web11901.mail.yahoo.com > > > > The #ifdef'ed solution doesn't cut it for sure. Let's see what better we > > can find ... > > Indeed. My preference option is to deploy dma_mmap_coherent() to > possible architectures and use it commonly in the ALSA core code. > > But, as a temporary workaround, I'm fine with ifdef until the API is > defined... There is a MIPS platform which may be based on a variety of system controllers only one of which supports cache coherency. So we want to deciede at runtime not at compile time. Ralf -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/