1 files changed, 17 insertions, 0 deletions

diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c
index b3eb8570cd7b..2c4892c853cf 100644
--- a/sound/soc/fsl/fsl_dma.c
+++ b/sound/soc/fsl/fsl_dma.c
@@ -697,6 +697,23 @@ static snd_pcm_uframes_t fsl_dma_pointer(struct snd_pcm_substream *substream)
         else
                 position = in_be32(&dma_channel->dar);
 
+        /*
+         * When capture is started, the SSI immediately starts to fill its FIFO.
+         * This means that the DMA controller is not started until the FIFO is
+         * full.  However, ALSA calls this function before that happens, when
+         * MR.DAR is still zero.  In this case, just return zero to indicate
+         * that nothing has been received yet.
+         */
+        if (!position)
+                return 0;
+
+        if ((position < dma_private->dma_buf_phys) ||
+            (position > dma_private->dma_buf_end)) {
+                dev_err(substream->pcm->card->dev,
+                        "dma pointer is out of range, halting stream\n");
+                return SNDRV_PCM_POS_XRUN;
+        }
+
         frames = bytes_to_frames(runtime, position - dma_private->dma_buf_phys);
 
         /*