ALSA: Fix allocation size calculation in snd_dma_alloc_pages_fallback()

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>

diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index f0c3b1d6da810f75c69b283f38b35fb3363f8950..a7b46ec72f3231191cb6f81d7c816f6b011bc696 100644 (file)
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -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;