ASoC: qcom: q6apm-lpass-dai: Fix multiple graph opens

commit 69acc48 upstream.

As prepare can be called mulitple times, this can result in multiple
graph opens for playback path.

This will result in a memory leaks, fix this by adding a check before
opening.

Fixes: be1fae6 ("ASoC: q6apm-lpass-dai: close graph on prepare errors")
Cc: Stable@vger.kernel.org
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
Link: https://patch.msgid.link/20260402081118.348071-5-srinivas.kandagatla@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Srinivas Kandagatla

sound/soc/qcom/qdsp6/q6apm-lpass-dais.c

@@ -175,7 +175,7 @@ static int q6apm_lpass_dai_prepare(struct snd_pcm_substream *substream, struct s
 	 * It is recommend to load DSP with source graph first and then sink
 	 * graph, so sequence for playback and capture will be different
 	 */
-	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && dai_data->graph[dai->id] == NULL) {
 		graph = q6apm_graph_open(dai->dev, NULL, dai->dev, graph_id);
 		if (IS_ERR(graph)) {
 			dev_err(dai->dev, "Failed to open graph (%d)\n", graph_id);