From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Subject: Re: [PATCH] ASoC: snd_dmaengine: add common api for pcm_mmap Date: Thu, 28 Jun 2012 14:30:26 +0200 Message-ID: <4FEC4E62.3020101@metafoo.de> References: <1340866886-24432-1-git-send-email-ldewangan@nvidia.com> <4FEC3B70.5030902@metafoo.de> <20120628121816.GB21029@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp-out-120.synserver.de (smtp-out-130.synserver.de [212.40.185.130]) by alsa0.perex.cz (Postfix) with ESMTP id 390A010402B for ; Thu, 28 Jun 2012 14:26:38 +0200 (CEST) In-Reply-To: <20120628121816.GB21029@sirena.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Mark Brown Cc: alsa-devel@alsa-project.org, swarren@nvidia.com, Takashi Iwai , linux-kernel@vger.kernel.org, Laxman Dewangan , lrg@ti.com, Marek Szyprowski List-Id: alsa-devel@alsa-project.org On 06/28/2012 02:18 PM, Mark Brown wrote: > On Thu, Jun 28, 2012 at 02:15:38PM +0200, Takashi Iwai wrote: >> Lars-Peter Clausen wrote: > >>> to the ALSA core. Now that there is a generic dma_mmap_writecombine it may >>> make sense to integrate this with snd_pcm_lib_default_mmap. > >> Agreed. > >> Also, it must be portable. So far, only ARM has >> dma_mmap_writecombine(), thus the build on other arch would fail as >> is. > > Oh, dear - this means we don't actually have a generic API at all. Is > there any effort being made to make this generally available? Yes there is, and in fact in next/master there is generic dma_mmap_writecombine. I'm not quite sure how it behaves on non ARM archs though. But in theory it should fallback to a normal coherent mapping. Marek did a lot of work on this, I've put him on Cc. - Lars