From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755921Ab2F2Q2u (ORCPT ); Fri, 29 Jun 2012 12:28:50 -0400 Received: from smtp-out-134.synserver.de ([212.40.185.134]:1178 "EHLO smtp-out-132.synserver.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752665Ab2F2Q2t (ORCPT ); Fri, 29 Jun 2012 12:28:49 -0400 X-SynServer-TrustedSrc: 1 X-SynServer-AuthUser: lars@metafoo.de X-SynServer-PPID: 25658 Message-ID: <4FEDD8A3.8000608@metafoo.de> Date: Fri, 29 Jun 2012 18:32:35 +0200 From: Lars-Peter Clausen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.4) Gecko/20120510 Icedove/10.0.4 MIME-Version: 1.0 To: Takashi Iwai CC: Laxman Dewangan , "lrg@ti.com" , "broonie@opensource.wolfsonmicro.com" , Stephen Warren , "perex@perex.cz" , "clemens@ladisch.de" , "alsa-devel@alsa-project.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 0/3] ASoC: Move pcm writecombine dma buffer allocation to core References: <1340965398-20872-1-git-send-email-ldewangan@nvidia.com> <4FEDC3F8.8000501@nvidia.com> <4FEDD29C.8040209@metafoo.de> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/29/2012 06:18 PM, Takashi Iwai wrote: > At Fri, 29 Jun 2012 18:06:52 +0200, > Lars-Peter Clausen wrote: >> >> On 06/29/2012 05:04 PM, Laxman Dewangan wrote: >>> [...] >>> >>> >>>> +/* allocate the coherent DMA pages */ >>>> +static void *snd_malloc_dev_pages(struct device *dev, size_t size, >>>> dma_addr_t *dma) >>>> +{ >>>> + return __snd_malloc_dev_pages(dev, size, dma, dma_alloc_coherent); >>> >>> This does not get compiled in ARM because dma_alloc_coherant is macro >>> defined as >>> >>> #define dma_alloc_coherent(d, s, h, f) dma_alloc_attrs(d, s, h, f, NULL) >>> >>> static inline void *dma_alloc_attrs(struct device *dev, size_t size, >>> dma_addr_t *dma_handle, gfp_t flag, >>> struct dma_attrs *attrs) >>> >>> >>> I fixed this by >>> static void *_dma_alloc_coherent(struct device *dev, size_t size, >>> dma_addr_t *dma_handle, gfp_t flag) >>> { >>> return dma_alloc_coherent(dev, size, dma_handle, flag); >>> } >>> >>> /* allocate the coherent DMA pages */ >>> static void *snd_malloc_dev_pages(struct device *dev, size_t size, >>> dma_addr_t *dma) >>> { >>> return _snd_malloc_dev_pages(dev, size, dma, _dma_alloc_coherent); >>> } >> >> I think all dma_alloc_* functions use dma_alloc_attrs internally these days. >> I think it might be a better idea just to use dma_alloc_attrs in >> __snd_malloc_dev_pages and just pass a dma_attrs struct instead of a function. >> >> Something like: >> >> static void *__snd_malloc_dev_pages(struct device *dev, size_t size, >> dma_addr_t *dma, struct dma_attrs *attrs) >> { >> .... >> res = dma_alloc_attrs(dev, PAGE_SIZE << pg, dma, gfp_flags, attrs); >> .... >> } >> >> >> static void *snd_malloc_dev_pages(struct device *dev, size_t size, >> dma_addr_t *dma) >> { >> return __snd_malloc_dev_pages(dev, size, dma, NULL); >> } >> >> static void *snd_malloc_dev_wc_pages(struct device *dev, size_t size, >> dma_addr_t *dma) >> { >> DEFINE_DMA_ATTRS(attrs); >> dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs); >> >> return __snd_malloc_dev_pages(dev, size, dma, &attrs); >> } >> >> Same applies for freeing the memory again. > > Yes, that'd be cleaner. > But I prefer the code still workable on 3.5-base kernel, which makes > easier to test and merge for 3.6, at first. Actually that part is already in 3.5. But I've just had a closer look and it looks as if even for 3.6 not all archs have been converted to dma_alloc_attrs yet :/