[PATCH] ASoC: fsl_asrc_dma: Fix dma_chan leak when config DMA channel failed

From: Xiyu Yang
Date: Mon May 25 2020 - 10:13:57 EST

fsl_asrc_dma_hw_params() invokes dma_request_channel() or
fsl_asrc_get_dma_channel(), which returns a reference of the specified
dma_chan object to "pair->dma_chan[dir]" with increased refcnt.

The reference counting issue happens in one exception handling path of
fsl_asrc_dma_hw_params(). When config DMA channel failed for Back-End,
the function forgets to decrease the refcnt increased by
dma_request_channel() or fsl_asrc_get_dma_channel(), causing a refcnt

Fix this issue by calling dma_release_channel() when config DMA channel

Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx>
Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>
sound/soc/fsl/fsl_asrc_dma.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
index e7178817d7a7..1ee10eafe3e6 100644
--- a/sound/soc/fsl/fsl_asrc_dma.c
+++ b/sound/soc/fsl/fsl_asrc_dma.c
@@ -252,6 +252,7 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
ret = dmaengine_slave_config(pair->dma_chan[dir], &config_be);
if (ret) {
dev_err(dev, "failed to config DMA channel for Back-End\n");
+ dma_release_channel(pair->dma_chan[dir]);
return ret;