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/include/sound/pcm.h b/include/sound/pcm.h
index 2389352..1691c7f 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -902,6 +902,7 @@
int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size);
int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream);
+#ifdef CONFIG_SND_DMA_SGBUF
/*
* SG-buffer handling
*/
@@ -927,6 +928,28 @@
unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
unsigned int ofs, unsigned int size);
+#else /* !SND_DMA_SGBUF */
+/*
+ * fake using a continuous buffer
+ */
+static inline dma_addr_t
+snd_pcm_sgbuf_get_addr(struct snd_pcm_substream *substream, unsigned int ofs)
+{
+ return substream->runtime->dma_addr + ofs;
+}
+
+static inline void *
+snd_pcm_sgbuf_get_ptr(struct snd_pcm_substream *substream, unsigned int ofs)
+{
+ return substream->runtime->dma_area + ofs;
+}
+
+#define snd_pcm_sgbuf_ops_page NULL
+
+#define snd_pcm_sgbuf_get_chunk_size(subs, ofs, size) (size)
+
+#endif /* SND_DMA_SGBUF */
+
/* handle mmap counter - PCM mmap callback should handle this counter properly */
static inline void snd_pcm_mmap_data_open(struct vm_area_struct *area)
{