| Message ID | 20191007082642.21798-1-alexandru.ardelean@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] iio: dac: ad7303: replace mlock with own lock | expand |
On Mon, 7 Oct 2019 11:26:42 +0300 Alexandru Ardelean <alexandru.ardelean@analog.com> wrote: > This change replaces indio_dev's mlock with the driver's own lock. The lock > is mostly needed to protect state when changing the `dac_cache` info. > The lock has been extended to `ad7303_read_raw()`, to make sure that the > cache is updated if an SPI-write is already in progress. > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > > Changelog v1 -> v2: > * remove lock from `ad7303_read_dac_powerdown()` > > drivers/iio/dac/ad7303.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/iio/dac/ad7303.c b/drivers/iio/dac/ad7303.c > index 8de9f40226e6..14bbac6bee98 100644 > --- a/drivers/iio/dac/ad7303.c > +++ b/drivers/iio/dac/ad7303.c > @@ -41,6 +41,7 @@ struct ad7303_state { > struct regulator *vdd_reg; > struct regulator *vref_reg; > > + struct mutex lock; > /* > * DMA (thus cache coherency maintenance) requires the > * transfer buffers to live in their own cache lines. > @@ -79,7 +80,7 @@ static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, > if (ret) > return ret; > > - mutex_lock(&indio_dev->mlock); > + mutex_lock(&st->lock); > > if (pwr_down) > st->config |= AD7303_CFG_POWER_DOWN(chan->channel); > @@ -90,7 +91,7 @@ static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, > * mode, so just write one of the DAC channels again */ > ad7303_write(st, chan->channel, st->dac_cache[chan->channel]); > > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&st->lock); > return len; > } > > @@ -116,7 +117,9 @@ static int ad7303_read_raw(struct iio_dev *indio_dev, > > switch (info) { > case IIO_CHAN_INFO_RAW: > + mutex_lock(&st->lock); > *val = st->dac_cache[chan->channel]; > + mutex_unlock(&st->lock); > return IIO_VAL_INT; > case IIO_CHAN_INFO_SCALE: > vref_uv = ad7303_get_vref(st, chan); > @@ -144,11 +147,11 @@ static int ad7303_write_raw(struct iio_dev *indio_dev, > if (val >= (1 << chan->scan_type.realbits) || val < 0) > return -EINVAL; > > - mutex_lock(&indio_dev->mlock); > + mutex_lock(&st->lock); > ret = ad7303_write(st, chan->address, val); > if (ret == 0) > st->dac_cache[chan->channel] = val; > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&st->lock); > break; > default: > ret = -EINVAL; > @@ -211,6 +214,8 @@ static int ad7303_probe(struct spi_device *spi) > > st->spi = spi; > > + mutex_init(&st->lock); > + > st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd"); > if (IS_ERR(st->vdd_reg)) > return PTR_ERR(st->vdd_reg);
diff --git a/drivers/iio/dac/ad7303.c b/drivers/iio/dac/ad7303.c index 8de9f40226e6..14bbac6bee98 100644 --- a/drivers/iio/dac/ad7303.c +++ b/drivers/iio/dac/ad7303.c @@ -41,6 +41,7 @@ struct ad7303_state { struct regulator *vdd_reg; struct regulator *vref_reg; + struct mutex lock; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. @@ -79,7 +80,7 @@ static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, if (ret) return ret; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); if (pwr_down) st->config |= AD7303_CFG_POWER_DOWN(chan->channel); @@ -90,7 +91,7 @@ static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, * mode, so just write one of the DAC channels again */ ad7303_write(st, chan->channel, st->dac_cache[chan->channel]); - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return len; } @@ -116,7 +117,9 @@ static int ad7303_read_raw(struct iio_dev *indio_dev, switch (info) { case IIO_CHAN_INFO_RAW: + mutex_lock(&st->lock); *val = st->dac_cache[chan->channel]; + mutex_unlock(&st->lock); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: vref_uv = ad7303_get_vref(st, chan); @@ -144,11 +147,11 @@ static int ad7303_write_raw(struct iio_dev *indio_dev, if (val >= (1 << chan->scan_type.realbits) || val < 0) return -EINVAL; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); ret = ad7303_write(st, chan->address, val); if (ret == 0) st->dac_cache[chan->channel] = val; - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); break; default: ret = -EINVAL; @@ -211,6 +214,8 @@ static int ad7303_probe(struct spi_device *spi) st->spi = spi; + mutex_init(&st->lock); + st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd"); if (IS_ERR(st->vdd_reg)) return PTR_ERR(st->vdd_reg);
This change replaces indio_dev's mlock with the driver's own lock. The lock is mostly needed to protect state when changing the `dac_cache` info. The lock has been extended to `ad7303_read_raw()`, to make sure that the cache is updated if an SPI-write is already in progress. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> --- Changelog v1 -> v2: * remove lock from `ad7303_read_dac_powerdown()` drivers/iio/dac/ad7303.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)