From: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx> As part of the general cleanup of indio_dev->mlock, this change replaces it with a local lock, to protect potential concurrent access to the completion callback during a conversion. This is part of a bigger cleanup. Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@xxxxxxxxxxxxxx/ Reviewed-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx> Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> --- drivers/iio/adc/exynos_adc.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c index 20477b249f2a..99f4404e9fd1 100644 --- a/drivers/iio/adc/exynos_adc.c +++ b/drivers/iio/adc/exynos_adc.c @@ -138,6 +138,16 @@ struct exynos_adc { bool read_ts; u32 ts_x; u32 ts_y; + + /* + * Lock to protect from potential concurrent access to the + * completion callback during a manual conversion. For this driver + * a wait-callback is used to wait for the conversion result, + * so in the meantime no other read request (or conversion start) + * must be performed, otherwise it would interfere with the + * current conversion result. + */ + struct mutex lock; }; struct exynos_adc_data { @@ -542,7 +552,7 @@ static int exynos_read_raw(struct iio_dev *indio_dev, return -EINVAL; } - mutex_lock(&indio_dev->mlock); + mutex_lock(&info->lock); reinit_completion(&info->completion); /* Select the channel to be used and Trigger conversion */ @@ -562,7 +572,7 @@ static int exynos_read_raw(struct iio_dev *indio_dev, ret = IIO_VAL_INT; } - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&info->lock); return ret; } @@ -573,7 +583,7 @@ static int exynos_read_s3c64xx_ts(struct iio_dev *indio_dev, int *x, int *y) unsigned long timeout; int ret; - mutex_lock(&indio_dev->mlock); + mutex_lock(&info->lock); info->read_ts = true; reinit_completion(&info->completion); @@ -598,7 +608,7 @@ static int exynos_read_s3c64xx_ts(struct iio_dev *indio_dev, int *x, int *y) } info->read_ts = false; - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&info->lock); return ret; } @@ -868,6 +878,8 @@ static int exynos_adc_probe(struct platform_device *pdev) indio_dev->channels = exynos_adc_iio_channels; indio_dev->num_channels = info->data->num_channels; + mutex_init(&info->lock); + ret = request_irq(info->irq, exynos_adc_isr, 0, dev_name(&pdev->dev), info); if (ret < 0) { -- 2.17.1
