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ALSA: Fix SG-buffer DMA with non-coherent architectures

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Using SG-buffers with dma_alloc_coherent() is often very inefficient
on non-coherent architectures because a tracking record could be
allocated in addition for each dma_alloc_coherent() call.
Instead, simply disable SG-buffers but just allocate normal continuous
buffers on non-supported (currently all but x86) architectures.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai
2008-06-17 16:39:06 +02:00
parent 8e4a718ff3
commit cc6a8acdee
6 changed files with 40 additions and 1 deletions
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4
sound/core/Kconfig
View File

@@ -206,4 +206,8 @@ config SND_PCM_XRUN_DEBUG
config SND_VMASTER
bool
config SND_DMA_SGBUF
def_bool y
depends on X86
source "sound/core/seq/Kconfig"

2
sound/core/Makefile
View File

@@ -13,7 +13,7 @@ snd-pcm-objs := pcm.o pcm_native.o pcm_lib.o pcm_timer.o pcm_misc.o \
pcm_memory.o
snd-page-alloc-y := memalloc.o
snd-page-alloc-$(CONFIG_HAS_DMA) += sgbuf.o
snd-page-alloc-$(CONFIG_SND_DMA_SGBUF) += sgbuf.o
snd-rawmidi-objs := rawmidi.o
snd-timer-objs := timer.o

4
sound/core/memalloc.c
View File

@@ -199,6 +199,8 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size,
case SNDRV_DMA_TYPE_DEV:
dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr);
break;
#endif
#ifdef CONFIG_SND_DMA_SGBUF
case SNDRV_DMA_TYPE_DEV_SG:
snd_malloc_sgbuf_pages(device, size, dmab, NULL);
break;
@@ -269,6 +271,8 @@ void snd_dma_free_pages(struct snd_dma_buffer *dmab)
case SNDRV_DMA_TYPE_DEV:
snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);
break;
#endif
#ifdef CONFIG_SND_DMA_SGBUF
case SNDRV_DMA_TYPE_DEV_SG:
snd_free_sgbuf_pages(dmab);
break;

2
sound/core/pcm_memory.c
View File

@@ -304,6 +304,7 @@ int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
EXPORT_SYMBOL(snd_pcm_lib_preallocate_pages_for_all);
#ifdef CONFIG_SND_DMA_SGBUF
/**
* snd_pcm_sgbuf_ops_page - get the page struct at the given offset
* @substream: the pcm substream instance
@@ -349,6 +350,7 @@ unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
return size;
}
EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size);
#endif /* CONFIG_SND_DMA_SGBUF */
/**
* snd_pcm_lib_malloc_pages - allocate the DMA buffer