From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 82CA8DDEF4 for ; Tue, 6 May 2008 09:44:30 +1000 (EST) Subject: Re: [PATCH] Sam440ep support From: Benjamin Herrenschmidt To: Gerhard Pircher In-Reply-To: <20080505195054.172000@gmx.net> References: <6DA6B1DA-11B5-4B89-88AD-561B4D17B33B@kernel.crashing.org> <20080505195054.172000@gmx.net> Content-Type: text/plain Date: Tue, 06 May 2008 09:44:18 +1000 Message-Id: <1210031058.21644.120.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, cjg@cruxppc.org Reply-To: benh@kernel.crashing.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2008-05-05 at 21:50 +0200, Gerhard Pircher wrote: > This is a (bad) hack that I also use on the AmigaOne to get the ALSA > sound > drivers working with DMA, because ALSA doesn't work with > dma-noncoherent.c. > The problem is the "nopage" mechanism, which fails with non coherent > DMA > allocations due to their own virtual address space (correct me, if I'm > wrong). > > See this thread for more info: > http://readlist.com/lists/vger.kernel.org/linux-kernel/45/226541.html > > This is a general problem that affects all powerpc boards that use > dma-noncoherent.c with ALSA PCI drivers. The link above doesn't provide any useful information on the problem and it contains itself a non working link... Can somebody explains exactly what's going on ? That shouldn't be hard to fix. I can't believe the problem has been around for 2 years and nobody actually bothered fixing it properly. Send me a sound card that needs that hack and I can take care of it myself. Ben.