[alsa-devel] [PATCH] ASoC: kirkwood: prevent double streaming

[Jean-Francois Moine]

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 at free.fr>
---
 sound/soc/kirkwood/kirkwood-dma.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sound/soc/kirkwood/kirkwood-dma.c b/sound/soc/kirkwood/kirkwood-dma.c
index 4cf2245..dbfdfe9 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);
-- 
2.1.4