prepare callback can be called multiple times, so unprepare the stream
if its already prepared.

Without this DSP is not happy to setting the params on a already
prepared graph.

Fixes: 9b4fe0f1cd79 ("ASoC: qdsp6: audioreach: add q6apm-dai support")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 sound/soc/qcom/qdsp6/q6apm-lpass-dais.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c b/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
index ce9e5646d8f3..23d23bc6fbaa 100644
--- a/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
+++ b/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
@@ -127,6 +127,11 @@ static int q6apm_lpass_dai_prepare(struct snd_pcm_substream *substream, struct s
 	int graph_id = dai->id;
 	int rc;
 
+	if (dai_data->is_port_started[dai->id]) {
+		q6apm_graph_stop(dai_data->graph[dai->id]);
+		dai_data->is_port_started[dai->id] = false;
+	}
+
 	/**
 	 * It is recommend to load DSP with source graph first and then sink
 	 * graph, so sequence for playback and capture will be different
-- 
2.21.0