From 73ba59b117a997307a1cbe3764fe08dae4c7edc1 Mon Sep 17 00:00:00 2001 From: Olivier Moysan Date: Tue, 26 Feb 2019 14:51:09 +0100 Subject: [PATCH] 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: Olivier Moysan Signed-off-by: Mark Brown --- sound/soc/stm/stm32_i2s.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/sound/soc/stm/stm32_i2s.c b/sound/soc/stm/stm32_i2s.c index 9edb753ffa1b4..42ce87a351048 100644 --- a/sound/soc/stm/stm32_i2s.c +++ b/sound/soc/stm/stm32_i2s.c @@ -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); -- 2.39.5