From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754608Ab2F1ODb (ORCPT ); Thu, 28 Jun 2012 10:03:31 -0400 Received: from cantor2.suse.de ([195.135.220.15]:41660 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751613Ab2F1OD3 (ORCPT ); Thu, 28 Jun 2012 10:03:29 -0400 Date: Thu, 28 Jun 2012 16:03:25 +0200 Message-ID: From: Takashi Iwai To: Lars-Peter Clausen Cc: Laxman Dewangan , "alsa-devel@alsa-project.org" , Stephen Warren , Mark Brown , "linux-kernel@vger.kernel.org" , "lrg@ti.com" Subject: Re: [alsa-devel] [PATCH] ASoC: snd_dmaengine: add common api for pcm_mmap In-Reply-To: <4FEC51BB.2040504@metafoo.de> References: <1340866886-24432-1-git-send-email-ldewangan@nvidia.com> <20120628105148.GD28922@opensource.wolfsonmicro.com> <4FEC468A.3080607@nvidia.com> <4FEC51BB.2040504@metafoo.de> User-Agent: Wanderlust/2.15.6 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.7 Emacs/23.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At Thu, 28 Jun 2012 14:44:43 +0200, Lars-Peter Clausen wrote: > > On 06/28/2012 01:56 PM, Laxman Dewangan wrote: > > On Thursday 28 June 2012 04:21 PM, Mark Brown wrote: > >> * PGP Signed by an unknown key > >> > >> On Thu, Jun 28, 2012 at 12:31:26PM +0530, Laxman Dewangan wrote: > >>> The pcm mmap for the substream dma buffer is done using the > >>> dma_mmap_writecombine(). > >>> Some of the chip sound driver like Spear, Tegra, Davinci, > >>> ep93xx,snd_imx, snd_mxs, NUC900, OMAP, Samsung are doing this > >>> mapping locally. > >>> Add api in the snd dmaengine driver so that different client of > >>> snd dmaengine can use this rather than implementing locally. > >> OK, but I'd expect this to come along with one or more patches > >> converting at least some of the users to the new API... > > > > This is effort towards moving the Tegra pcm driver for dmangine based dma > > driver inplace of legacy dma driver for Tegra which have private API. > > > > Currently, following 4 pcm driver can use this API directly keeping that > > they already using the generic snd dmaengine pcm driver. > > ep93xx, > > spear, > > fsl, > > mxs. > > And Tegra will be next. > > > > Other driver which can use this API are davinci, OMAP, samsung but because > > they are not using the snd_dmaengine_pcm driver's api as of now so not be > > very much useful for them. > > Btw. all these drivers basically use the same code for buffer preallocation. > Since how the buffer is mmaped is related to how it is allocated it might be > worth to factor this out at the same time as well. Hrm. Do you mean hacking more on sound/core/memalloc.c, or sanitize all these stuff? Adding dma_alloc_writecombine() variant is easy, but at the same time, I also would like to rip off this ugly thing. Takashi