From: Andreas Pape <apape@xxxxxxxxxxxxxx>
Setting pointer and afterwards check for wrap around leads
to the possibility of returning the inconsistent pointer position.
This patch increments buffer pointer atomically to avoid this issue.
Signed-off-by: Andreas Pape <apape@xxxxxxxxxxxxxx>
Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
---
sound/core/pcm_dmaengine.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
index 8eb58c7..6f6da11 100644
--- a/sound/core/pcm_dmaengine.c
+++ b/sound/core/pcm_dmaengine.c
@@ -139,12 +139,14 @@ EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
static void dmaengine_pcm_dma_complete(void *arg)
{
+ unsigned int new_pos;
struct snd_pcm_substream *substream = arg;
struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
- prtd->pos += snd_pcm_lib_period_bytes(substream);
- if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
- prtd->pos = 0;
+ new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream);
+ if (new_pos >= snd_pcm_lib_buffer_bytes(substream))
+ new_pos = 0;
+ prtd->pos = new_pos;
snd_pcm_period_elapsed(substream);
}
--
2.9.3
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