Messages in this thread | | | Date | Fri, 29 Jun 2012 18:18:56 +0200 | From | Takashi Iwai <> | Subject | Re: [PATCH 0/3] ASoC: Move pcm writecombine dma buffer allocation to core |
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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.
So, let's clean up these indirect calls once after all things are settled down at 3.6-rc1. It can be applied even before 3.6-rc2.
Takashi
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