Messages in this thread Patch in this message | | | From | Eugeniu Rosca <> | Subject | [PATCH] ALSA: dmaengine: increment buffer pointer atomically | Date | Mon, 26 Sep 2022 18:58:13 +0200 |
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From: Andreas Pape <apape@de.adit-jv.com>
Setting pointer and afterwards checking for wraparound leads to the possibility of returning the inconsistent pointer position.
This patch increments buffer pointer atomically to avoid this issue.
Fixes: e7f73a1613567a ("ASoC: Add dmaengine PCM helper functions") Signed-off-by: Andreas Pape <apape@de.adit-jv.com> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com> --- 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 5b2ca028f5aa..494ec0c207fa 100644 --- a/sound/core/pcm_dmaengine.c +++ b/sound/core/pcm_dmaengine.c @@ -133,12 +133,14 @@ 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); } -- 2.37.2
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