ALSA: pcm: Fix missing check of the new non-cached buffer type
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Message ID
State New
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  • ALSA: pcm: Fix missing check of the new non-cached buffer type
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Commit Message

Takashi Iwai Nov. 4, 2019, 10:11 a.m. UTC
The check for the mmap support via hw_support_mmap() function misses
the case where the device is with SNDRV_DMA_TYPE_DEV_UC, which should
have been treated equally as SNDRV_DMA_TYPE_DEV.  Let's fix it.

Note that this bug doesn't hit any practical problem, because
SNDRV_DMA_TYPE_DEV_UC is used only for x86-specific drivers
(snd-hda-intel and snd-intel8x0) for the specific platforms that need
the non-cached buffers.  And, on such platforms, hw_support_mmap()
already returns true in anyway.  That's the reason I didn't put
Cc-to-stable mark here.  This is only for any theoretical future

Fixes: 425da159707b ("ALSA: pcm: use dma_can_mmap() to check if a device supports dma_mmap_*")
Fixes: 42e748a0b325 ("ALSA: memalloc: Add non-cached buffer type")
Signed-off-by: Takashi Iwai <>
 sound/core/pcm_native.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff mbox series

diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 91c6ad58729f..c3a139436ac2 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -222,7 +222,8 @@  static bool hw_support_mmap(struct snd_pcm_substream *substream)
 		return false;
 	if (substream->ops->mmap ||
-	    substream-> != SNDRV_DMA_TYPE_DEV)
+	    (substream-> != SNDRV_DMA_TYPE_DEV &&
+	     substream-> != SNDRV_DMA_TYPE_DEV_UC))
 		return true;
 	return dma_can_mmap(substream->;