1 files changed, 33 insertions, 7 deletions

diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
index ff07b4a9992..a6d42808828 100644
--- 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)
@@ -326,6 +324,32 @@ 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);
+
 /**
  * snd_pcm_lib_malloc_pages - allocate the DMA buffer
  * @substream: the substream to allocate the DMA buffer to
@@ -342,10 +366,12 @@ 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 +417,9 @@ 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) {