ALSA: pxa2xx: Fix unlocked snd_pcm_stop() call

snd_pcm_stop() must be called in the PCM substream lock context.

Cc: <stable@vger.kernel.org>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/arm/pxa2xx-pcm-lib.c b/sound/arm/pxa2xx-pcm-lib.c
index 76e0d56..823359e 100644
--- a/sound/arm/pxa2xx-pcm-lib.c
+++ b/sound/arm/pxa2xx-pcm-lib.c
@@ -166,7 +166,9 @@
 	} else {
 		printk(KERN_ERR "%s: DMA error on channel %d (DCSR=%#x)\n",
 			rtd->params->name, dma_ch, dcsr);
+		snd_pcm_stream_lock(substream);
 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+		snd_pcm_stream_unlock(substream);
 	}
 }
 EXPORT_SYMBOL(pxa2xx_pcm_dma_irq);