ALSA: Fix SG-buffer DMA with non-coherent architectures
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>
diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
index a6d4280..caa7796 100644
--- a/sound/core/pcm_memory.c
+++ b/sound/core/pcm_memory.c
@@ -304,6 +304,7 @@
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 @@
return size;
}
EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size);
+#endif /* CONFIG_SND_DMA_SGBUF */
/**
* snd_pcm_lib_malloc_pages - allocate the DMA buffer
