ALSA: pcm_dmaengine: Don't synchronize DMA channel when DMA is paused

commit 88e98af upstream.

When suspended, the DMA channel may enter PAUSE state if dmaengine_pause()
is supported by DMA.
At this state, dmaengine_synchronize() should not be called, otherwise
the DMA channel can't be resumed successfully.

Fixes: e834341 ("ALSA: dmaengine: Synchronize dma channel after drop()")
Signed-off-by: Shengjiu Wang <[email protected]>
Cc: <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Takashi Iwai <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

sound/core/pcm_dmaengine.c

@@ -352,8 +352,12 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 int snd_dmaengine_pcm_sync_stop(struct snd_pcm_substream *substream)
 {
 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	struct dma_tx_state state;
+	enum dma_status status;
 
-	dmaengine_synchronize(prtd->dma_chan);
+	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
+	if (status != DMA_PAUSED)
+		dmaengine_synchronize(prtd->dma_chan);
 
 	return 0;
 }