ALSA: Fix allocation size calculation in snd_dma_alloc_pages_fallback()
Takashi Iwai [Wed, 30 Jul 2008 13:13:33 +0000 (15:13 +0200)]
snd_dma_alloc_pages_fallback() always tries to reduce the size in a half,
but it's not good when the given size isn't a power-of-two.
Check it first then try to align.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/core/memalloc.c

index f0c3b1d..a7b46ec 100644 (file)
@@ -277,11 +277,16 @@ int snd_dma_alloc_pages_fallback(int type, struct device *device, size_t size,
        int err;
 
        while ((err = snd_dma_alloc_pages(type, device, size, dmab)) < 0) {
+               size_t aligned_size;
                if (err != -ENOMEM)
                        return err;
-               size >>= 1;
                if (size <= PAGE_SIZE)
                        return -ENOMEM;
+               aligned_size = PAGE_SIZE << get_order(size);
+               if (size != aligned_size)
+                       size = aligned_size;
+               else
+                       size >>= 1;
        }
        if (! dmab->area)
                return -ENOMEM;