linux-kernel - [PATCH] ASoC: dmaengine_pcm: terminate dmaengine before synchronize

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Date: Tue,  4 Jun 2024 16:58:57 +0800
From: Shengjiu Wang <shengjiu.wang@....com>
To: lars@...afoo.de,
	perex@...ex.cz,
	tiwai@...e.com,
	linux-sound@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	alsa-devel@...a-project.org,
	shengjiu.wang@...il.com
Subject: [PATCH] ASoC: dmaengine_pcm: terminate dmaengine before synchronize

When dmaengine supports pause function, in suspend state,
dmaengine_pause() is called instead of dmaengine_terminate_async(),

In end of playback stream, the runtime->state will go to
SNDRV_PCM_STATE_DRAINING, if system suspend & resume happen
at this time, application will not resume playback stream, the
stream will be closed directly, the dmaengine_terminate_async()
will not be called before the dmaengine_synchronize(), which
violates the call sequence for dmaengine_synchronize().

This behavior also happens for capture streams, but there is no
SNDRV_PCM_STATE_DRAINING state for capture. So use
dmaengine_tx_status() to check the DMA status if the status is
DMA_PAUSED, then call dmaengine_terminate_async() to terminate
dmaengine before dmaengine_synchronize().

Signed-off-by: Shengjiu Wang <shengjiu.wang@....com>
---
 sound/core/pcm_dmaengine.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
index 12aa1cef11a1..7346c993a067 100644
--- a/sound/core/pcm_dmaengine.c
+++ b/sound/core/pcm_dmaengine.c
@@ -358,6 +358,12 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
 {
 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	struct dma_tx_state state;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
+	if (status == DMA_PAUSED)
+		dmaengine_terminate_async(prtd->dma_chan);

 	dmaengine_synchronize(prtd->dma_chan);
 	kfree(prtd);
@@ -378,6 +384,12 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
 {
 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+	struct dma_tx_state state;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
+	if (status == DMA_PAUSED)
+		dmaengine_terminate_async(prtd->dma_chan);

 	dmaengine_synchronize(prtd->dma_chan);
 	dma_release_channel(prtd->dma_chan);
-- 
2.34.1