Unverified Commit 26f98e82 authored by Olivier Moysan's avatar Olivier Moysan Committed by Mark Brown
Browse files

ASoC: stm32: sai: fix race condition in irq handler 



When snd_pcm_stop_xrun() is called in interrupt routine,
substream context may have already been released.
Add protection on substream context.

Signed-off-by: default avatarOlivier Moysan <olivier.moysan@st.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent b8468192

sound/soc/stm/stm32_sai_sub.c

+12 −1
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ 
 * @spdif_frm_cnt: S/PDIF playback frame counter

 * @iec958: iec958 data

 * @ctrl_lock: control lock

 * @irq_lock: prevent race condition with IRQ

 */

struct stm32_sai_sub_data {

	struct platform_device *pdev;
@@ -133,6 +134,7 @@ struct stm32_sai_sub_data { 
	unsigned int spdif_frm_cnt;

	struct snd_aes_iec958 iec958;

	struct mutex ctrl_lock; /* protect resources accessed by controls */

	spinlock_t irq_lock; /* used to prevent race condition with IRQ */

};



enum stm32_sai_fifo_th {
@@ -474,8 +476,10 @@ static irqreturn_t stm32_sai_isr(int irq, void *devid) 
		status = SNDRV_PCM_STATE_XRUN;

	}



	if (status != SNDRV_PCM_STATE_RUNNING)

	spin_lock(&sai->irq_lock);

	if (status != SNDRV_PCM_STATE_RUNNING && sai->substream)

		snd_pcm_stop_xrun(sai->substream);

	spin_unlock(&sai->irq_lock);



	return IRQ_HANDLED;

}
@@ -679,8 +683,11 @@ static int stm32_sai_startup(struct snd_pcm_substream *substream, 
{

	struct stm32_sai_sub_data *sai = snd_soc_dai_get_drvdata(cpu_dai);

	int imr, cr2, ret;

	unsigned long flags;



	spin_lock_irqsave(&sai->irq_lock, flags);

	sai->substream = substream;

	spin_unlock_irqrestore(&sai->irq_lock, flags);



	if (STM_SAI_PROTOCOL_IS_SPDIF(sai)) {

		snd_pcm_hw_constraint_mask64(substream->runtime,
@@ -1059,6 +1066,7 @@ static void stm32_sai_shutdown(struct snd_pcm_substream *substream, 
			       struct snd_soc_dai *cpu_dai)

{

	struct stm32_sai_sub_data *sai = snd_soc_dai_get_drvdata(cpu_dai);

	unsigned long flags;



	regmap_update_bits(sai->regmap, STM_SAI_IMR_REGX, SAI_XIMR_MASK, 0);
@@ -1069,7 +1077,9 @@ static void stm32_sai_shutdown(struct snd_pcm_substream *substream, 


	clk_rate_exclusive_put(sai->sai_mclk);



	spin_lock_irqsave(&sai->irq_lock, flags);

	sai->substream = NULL;

	spin_unlock_irqrestore(&sai->irq_lock, flags);

}



static int stm32_sai_pcm_new(struct snd_soc_pcm_runtime *rtd,
@@ -1433,6 +1443,7 @@ static int stm32_sai_sub_probe(struct platform_device *pdev) 


	sai->pdev = pdev;

	mutex_init(&sai->ctrl_lock);

	spin_lock_init(&sai->irq_lock);

	platform_set_drvdata(pdev, sai);



	sai->pdata = dev_get_drvdata(pdev->dev.parent);