On Wed, 16 Sep 2020 12:31:23 +0300 Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote: > 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> Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > 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) {
