ASoC: kirkwood: prevent double streaming

The kirkwood audio subsystem presents 2 PCM's for one source.
Streaming on a second PCM while the first one is active
cuts this last one.
Then, ending the last stream gives a kernel trap in free_irq().

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/sound/soc/kirkwood/kirkwood-dma.c b/sound/soc/kirkwood/kirkwood-dma.c
index 4cf2245950d7..dbfdfe99c69d 100644
--- a/sound/soc/kirkwood/kirkwood-dma.c
+++ b/sound/soc/kirkwood/kirkwood-dma.c
@@ -148,10 +148,14 @@ static int kirkwood_dma_open(struct snd_pcm_substream *substream)
         dram = mv_mbus_dram_info();
         addr = substream->dma_buffer.addr;
         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+                if (priv->substream_play)
+                        return -EBUSY;
                 priv->substream_play = substream;
                 kirkwood_dma_conf_mbus_windows(priv->io,
                         KIRKWOOD_PLAYBACK_WIN, addr, dram);
         } else {
+                if (priv->substream_rec)
+                        return -EBUSY;
                 priv->substream_rec = substream;
                 kirkwood_dma_conf_mbus_windows(priv->io,
                         KIRKWOOD_RECORD_WIN, addr, dram);