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Unverified Commit 3005decf authored by Olivier Moysan's avatar Olivier Moysan Committed by Mark Brown
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ASoC: stm32: i2s: 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 88dce52e

sound/soc/stm/stm32_i2s.c

+14 −3
Original line number Diff line number Diff line
@@ -201,6 +201,7 @@ enum i2s_datlen { 
 * @base:  mmio register base virtual address

 * @phys_addr: I2S registers physical base address

 * @lock_fd: lock to manage race conditions in full duplex mode

 * @irq_lock: prevent race condition with IRQ

 * @dais_name: DAI name

 * @mclk_rate: master clock frequency (Hz)

 * @fmt: DAI protocol
@@ -222,6 +223,7 @@ struct stm32_i2s_data { 
	void __iomem *base;

	dma_addr_t phys_addr;

	spinlock_t lock_fd; /* Manage race conditions for full duplex */

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

	char dais_name[STM32_I2S_DAI_NAME_SIZE];

	unsigned int mclk_rate;

	unsigned int fmt;
@@ -263,8 +265,10 @@ static irqreturn_t stm32_i2s_isr(int irq, void *devid) 
	if (flags & I2S_SR_TIFRE)

		dev_dbg(&pdev->dev, "Frame error\n");



	if (err)

	spin_lock(&i2s->irq_lock);

	if (err && i2s->substream)

		snd_pcm_stop_xrun(i2s->substream);

	spin_unlock(&i2s->irq_lock);



	return IRQ_HANDLED;

}
@@ -540,9 +544,12 @@ static int stm32_i2s_startup(struct snd_pcm_substream *substream, 
			     struct snd_soc_dai *cpu_dai)

{

	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);

	unsigned long flags;

	int ret;



	spin_lock_irqsave(&i2s->irq_lock, flags);

	i2s->substream = substream;

	spin_unlock_irqrestore(&i2s->irq_lock, flags);



	ret = clk_prepare_enable(i2s->i2sclk);

	if (ret < 0) {
@@ -673,13 +680,16 @@ static void stm32_i2s_shutdown(struct snd_pcm_substream *substream, 
			       struct snd_soc_dai *cpu_dai)

{

	struct stm32_i2s_data *i2s = snd_soc_dai_get_drvdata(cpu_dai);



	i2s->substream = NULL;

	unsigned long flags;



	regmap_update_bits(i2s->regmap, STM32_I2S_CGFR_REG,

			   I2S_CGFR_MCKOE, (unsigned int)~I2S_CGFR_MCKOE);



	clk_disable_unprepare(i2s->i2sclk);



	spin_lock_irqsave(&i2s->irq_lock, flags);

	i2s->substream = NULL;

	spin_unlock_irqrestore(&i2s->irq_lock, flags);

}



static int stm32_i2s_dai_probe(struct snd_soc_dai *cpu_dai)
@@ -874,6 +884,7 @@ static int stm32_i2s_probe(struct platform_device *pdev) 
	i2s->pdev = pdev;

	i2s->ms_flg = I2S_MS_NOT_SET;

	spin_lock_init(&i2s->lock_fd);

	spin_lock_init(&i2s->irq_lock);

	platform_set_drvdata(pdev, i2s);



	ret = stm32_i2s_dais_init(pdev, i2s);