Unverified Commit 84222ef5 authored by Srinivas Kandagatla's avatar Srinivas Kandagatla Committed by Mark Brown
Browse files

ASoC: qcom: q6apm-dai: fix race condition while updating the position pointer 



It is noticed that the position pointer value seems to get a get corrupted
due to missing locking between updating and reading.

Fix this by adding a spinlock around the position pointer.

Fixes: 9b4fe0f1 ("ASoC: qdsp6: audioreach: add q6apm-dai support")
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230209122806.18923-3-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent c2ac3aec

sound/soc/qcom/qdsp6/q6apm-dai.c

+15 −1
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/slab.h>

#include <sound/soc.h>

#include <sound/soc-dapm.h>

#include <linux/spinlock.h>

#include <sound/pcm.h>

#include <asm/dma.h>

#include <linux/dma-mapping.h>
@@ -53,6 +54,7 @@ struct q6apm_dai_rtd { 
	uint16_t session_id;

	enum stream_state state;

	struct q6apm_graph *graph;

	spinlock_t lock;

};



struct q6apm_dai_data {
@@ -99,20 +101,25 @@ static void event_handler(uint32_t opcode, uint32_t token, uint32_t *payload, vo 
{

	struct q6apm_dai_rtd *prtd = priv;

	struct snd_pcm_substream *substream = prtd->substream;

	unsigned long flags;



	switch (opcode) {

	case APM_CLIENT_EVENT_CMD_EOS_DONE:

		prtd->state = Q6APM_STREAM_STOPPED;

		break;

	case APM_CLIENT_EVENT_DATA_WRITE_DONE:

	        spin_lock_irqsave(&prtd->lock, flags);

		prtd->pos += prtd->pcm_count;

		spin_unlock_irqrestore(&prtd->lock, flags);

		snd_pcm_period_elapsed(substream);

		if (prtd->state == Q6APM_STREAM_RUNNING)

			q6apm_write_async(prtd->graph, prtd->pcm_count, 0, 0, 0);



		break;

	case APM_CLIENT_EVENT_DATA_READ_DONE:

	        spin_lock_irqsave(&prtd->lock, flags);

		prtd->pos += prtd->pcm_count;

		spin_unlock_irqrestore(&prtd->lock, flags);

		snd_pcm_period_elapsed(substream);

		if (prtd->state == Q6APM_STREAM_RUNNING)

			q6apm_read(prtd->graph);
@@ -253,6 +260,7 @@ static int q6apm_dai_open(struct snd_soc_component *component, 
	if (prtd == NULL)

		return -ENOMEM;



	spin_lock_init(&prtd->lock);

	prtd->substream = substream;

	prtd->graph = q6apm_graph_open(dev, (q6apm_cb)event_handler, prtd, graph_id);

	if (IS_ERR(prtd->graph)) {
@@ -332,11 +340,17 @@ static snd_pcm_uframes_t q6apm_dai_pointer(struct snd_soc_component *component, 
{

	struct snd_pcm_runtime *runtime = substream->runtime;

	struct q6apm_dai_rtd *prtd = runtime->private_data;

	snd_pcm_uframes_t ptr;

	unsigned long flags;



	spin_lock_irqsave(&prtd->lock, flags);

	if (prtd->pos == prtd->pcm_size)

		prtd->pos = 0;



	return bytes_to_frames(runtime, prtd->pos);

	ptr =  bytes_to_frames(runtime, prtd->pos);

	spin_unlock_irqrestore(&prtd->lock, flags);



	return ptr;

}



static int q6apm_dai_hw_params(struct snd_soc_component *component,