dma_request_slave_channel() may return NULL which will lead to
NULL pointer dereference error in 'tmp_chan->private'.
Correct this behaviour by, first, switching from deprecated function
dma_request_slave_channel() to dma_request_chan(). Secondly, enable
sanity check for the resuling value of dma_request_chan().
Also, fix description that follows the enacted changes and that
concerns the use of dma_request_slave_channel().
Fixes: 706e2c881158 ("ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End")
Co-developed-by: Natalia Petrova <n.petrova@xxxxxxxxxx>
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
---
sound/soc/fsl/fsl_asrc_dma.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
index 3b81a465814a..05a7d1588d20 100644
--- a/sound/soc/fsl/fsl_asrc_dma.c
+++ b/sound/soc/fsl/fsl_asrc_dma.c
@@ -209,14 +209,19 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
be_chan = soc_component_to_pcm(component_be)->chan[substream->stream];
tmp_chan = be_chan;
}
- if (!tmp_chan)
- tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");
+ if (!tmp_chan) {
+ tmp_chan = dma_request_chan(dev_be, tx ? "tx" : "rx");
+ if (IS_ERR(tmp_chan)) {
+ dev_err(dev, "failed to request DMA channel for Back-End\n");
+ return -EINVAL;
+ }
+ }
/*
* An EDMA DEV_TO_DEV channel is fixed and bound with DMA event of each
* peripheral, unlike SDMA channel that is allocated dynamically. So no
* need to configure dma_request and dma_request2, but get dma_chan of
- * Back-End device directly via dma_request_slave_channel.
+ * Back-End device directly via dma_request_chan.
*/
if (!asrc->use_edma) {
/* Get DMA request of Back-End */
