On Mon, 28 Sep 2020 16:13:30 +0300 Mircea Caprioru <mircea.caprioru@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 on the device's state structure. > > This is part of a bigger cleanup. > Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@xxxxxxxxxxxxxx/ > > Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx> > Signed-off-by: Mircea Caprioru <mircea.caprioru@xxxxxxxxxx> Applied, Thanks, Jonathan > --- > drivers/iio/adc/palmas_gpadc.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c > index 889b88768b63..14874f11614d 100644 > --- a/drivers/iio/adc/palmas_gpadc.c > +++ b/drivers/iio/adc/palmas_gpadc.c > @@ -90,6 +90,12 @@ static struct palmas_gpadc_info palmas_gpadc_info[] = { > * 3: 800 uA > * @extended_delay: enable the gpadc extended delay mode > * @auto_conversion_period: define the auto_conversion_period > + * @lock: Lock to protect the device state during a potential concurrent > + * read access from userspace. Reading a raw value requires a sequence > + * of register writes, then a wait for a completion callback, > + * and finally a register read, during which userspace could issue > + * another read request. This lock protects a read access from > + * ocurring before another one has finished. > * > * This is the palmas_gpadc structure to store run-time information > * and pointers for this driver instance. > @@ -110,6 +116,7 @@ struct palmas_gpadc { > bool wakeup1_enable; > bool wakeup2_enable; > int auto_conversion_period; > + struct mutex lock; > }; > > /* > @@ -388,7 +395,7 @@ static int palmas_gpadc_read_raw(struct iio_dev *indio_dev, > if (adc_chan > PALMAS_ADC_CH_MAX) > return -EINVAL; > > - mutex_lock(&indio_dev->mlock); > + mutex_lock(&adc->lock); > > switch (mask) { > case IIO_CHAN_INFO_RAW: > @@ -414,12 +421,12 @@ static int palmas_gpadc_read_raw(struct iio_dev *indio_dev, > goto out; > } > > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&adc->lock); > return ret; > > out: > palmas_gpadc_read_done(adc, adc_chan); > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&adc->lock); > > return ret; > } > @@ -516,6 +523,9 @@ static int palmas_gpadc_probe(struct platform_device *pdev) > adc->dev = &pdev->dev; > adc->palmas = dev_get_drvdata(pdev->dev.parent); > adc->adc_info = palmas_gpadc_info; > + > + mutex_init(&adc->lock); > + > init_completion(&adc->conv_completion); > dev_set_drvdata(&pdev->dev, indio_dev); >
