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

[pandora-kernel.git] / sound / core / pcm_memory.c

diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
index ff07b4a..caa7796 100644 (file)
--- a/sound/core/pcm_memory.c
+++ b/sound/core/pcm_memory.c
@@ -50,8 +50,6 @@ static int preallocate_pcm_pages(struct snd_pcm_substream *substream, size_t siz
        struct snd_dma_buffer *dmab = &substream->dma_buffer;
        int err;
 
-       snd_assert(size > 0, return -EINVAL);
-
        /* already reserved? */
        if (snd_dma_get_reserved_buf(dmab, substream->dma_buf_id) > 0) {
                if (dmab->bytes >= size)
@@ -306,6 +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
@@ -326,6 +325,33 @@ struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigne
 
 EXPORT_SYMBOL(snd_pcm_sgbuf_ops_page);
 
+/*
+ * compute the max chunk size with continuous pages on sg-buffer
+ */
+unsigned int snd_pcm_sgbuf_get_chunk_size(struct snd_pcm_substream *substream,
+                                         unsigned int ofs, unsigned int size)
+{
+       struct snd_sg_buf *sg = snd_pcm_substream_sgbuf(substream);
+       unsigned int start, end, pg;
+
+       start = ofs >> PAGE_SHIFT;
+       end = (ofs + size - 1) >> PAGE_SHIFT;
+       /* check page continuity */
+       pg = sg->table[start].addr >> PAGE_SHIFT;
+       for (;;) {
+               start++;
+               if (start > end)
+                       break;
+               pg++;
+               if ((sg->table[start].addr >> PAGE_SHIFT) != pg)
+                       return (start << PAGE_SHIFT) - ofs;
+       }
+       /* ok, all on continuous pages */
+       return size;
+}
+EXPORT_SYMBOL(snd_pcm_sgbuf_get_chunk_size);
+#endif /* CONFIG_SND_DMA_SGBUF */
+
 /**
  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
  * @substream: the substream to allocate the DMA buffer to
@@ -342,10 +368,12 @@ int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size)
        struct snd_pcm_runtime *runtime;
        struct snd_dma_buffer *dmab = NULL;
 
-       snd_assert(substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_UNKNOWN, return -EINVAL);
-       snd_assert(substream != NULL, return -EINVAL);
+       if (PCM_RUNTIME_CHECK(substream))
+               return -EINVAL;
+       if (snd_BUG_ON(substream->dma_buffer.dev.type ==
+                      SNDRV_DMA_TYPE_UNKNOWN))
+               return -EINVAL;
        runtime = substream->runtime;
-       snd_assert(runtime != NULL, return -EINVAL);
 
        if (runtime->dma_buffer_p) {
                /* perphaps, we might free the large DMA memory region
@@ -391,9 +419,9 @@ int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
 {
        struct snd_pcm_runtime *runtime;
 
-       snd_assert(substream != NULL, return -EINVAL);
+       if (PCM_RUNTIME_CHECK(substream))
+               return -EINVAL;
        runtime = substream->runtime;
-       snd_assert(runtime != NULL, return -EINVAL);
        if (runtime->dma_area == NULL)
                return 0;
        if (runtime->dma_buffer_p != &substream->dma_buffer) {