[PATCH 3/5] ASoC: fsl_asrc_dma: release DMA channels on repeated

[Stefan Ghetu <stefan.ghetu@nxp.com>]

fsl_asrc_dma_hw_params() requests new DMA channels on every call and
overwrites the previous ones, which are leaked when hw_params() is
called again without hw_free(). Its Back-End error path also releases a
channel without clearing the pointer, so the following hw_free()
releases it a second time.

Release the channels of a previous call first, and clear the pointer in
the error path.

Fixes: 3117bb3109dc ("ASoC: fsl_asrc: Add ASRC ASoC CPU DAI and platform drivers")
Fixes: 36124fb19f1a ("ASoC: fsl_asrc_dma: Fix dma_chan leak when config DMA channel failed")
Signed-off-by: Stefan Ghetu <stefan.ghetu@nxp.com>
---
 sound/soc/fsl/fsl_asrc_dma.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
index b417de6abebe..5ba4bdeff019 100644
--- a/sound/soc/fsl/fsl_asrc_dma.c
+++ b/sound/soc/fsl/fsl_asrc_dma.c
@@ -124,6 +124,19 @@ static int fsl_asrc_dma_trigger(struct snd_soc_component *component,
 	return 0;
 }
 
+static void fsl_asrc_dma_release_chans(struct fsl_asrc_pair *pair, u8 dir)
+{
+	if (pair->dma_chan[!dir])
+		dma_release_channel(pair->dma_chan[!dir]);
+
+	/* release dev_to_dev chan if we aren't reusing the Back-End one */
+	if (pair->dma_chan[dir] && pair->req_dma_chan)
+		dma_release_channel(pair->dma_chan[dir]);
+
+	pair->dma_chan[!dir] = NULL;
+	pair->dma_chan[dir] = NULL;
+}
+
 static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 				  struct snd_pcm_substream *substream,
 				  struct snd_pcm_hw_params *params)
@@ -190,6 +203,9 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 	dma_params_fe->addr = asrc->paddr + asrc->get_fifo_addr(!dir, index);
 	dma_params_fe->maxburst = dma_params_be->maxburst;
 
+	/* hw_params() may be called again without hw_free() in between */
+	fsl_asrc_dma_release_chans(pair, dir);
+
 	tmp_chan = asrc->get_dma_channel(pair, !dir);
 	if (IS_ERR(tmp_chan)) {
 		dev_err(dev, "failed to request DMA channel\n");
@@ -342,6 +358,7 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 		dev_err(dev, "failed to config DMA channel for Back-End\n");
 		if (pair->req_dma_chan)
 			dma_release_channel(pair->dma_chan[dir]);
+		pair->dma_chan[dir] = NULL;
 		return ret;
 	}
 
@@ -356,15 +373,7 @@ static int fsl_asrc_dma_hw_free(struct snd_soc_component *component,
 	struct fsl_asrc_pair *pair = runtime->private_data;
 	u8 dir = tx ? OUT : IN;
 
-	if (pair->dma_chan[!dir])
-		dma_release_channel(pair->dma_chan[!dir]);
-
-	/* release dev_to_dev chan if we aren't reusing the Back-End one */
-	if (pair->dma_chan[dir] && pair->req_dma_chan)
-		dma_release_channel(pair->dma_chan[dir]);
-
-	pair->dma_chan[!dir] = NULL;
-	pair->dma_chan[dir] = NULL;
+	fsl_asrc_dma_release_chans(pair, dir);
 
 	return 0;
 }
-- 
2.53.0