| Message ID | ec1848899e808fd5544bb1ca640abdc48fdfd6f3.1517845616.git.shreeya.patel23498@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2018-02-06 at 01:10 +0530, Shreeya Patel wrote: > iio_dev->mlock is to be used only by the IIO core for protecting > device mode changes between INDIO_DIRECT and INDIO_BUFFER. > > This patch replaces the use of mlock with the already established > buf_lock mutex. > > Introducing 'unlocked' forms of read and write registers. The > read/write frequency functions now require buf_lock to be held. > That's not obvious so avoid this but moving the locking inside > the functions where it is then clear that they are taking the > unlocked forms of the register read/write. > > It isn't readily apparent that write frequency function requires > the locks to be taken, so move it inside the function to where it > is required to protect. Removed linux-kernel list & Greg from reply list. > > Signed-off-by: Shreeya Patel <shreeya.patel23498@gmail.com> > --- > > Changes in v2 > -Add static keyword to newly introduced functions and remove some > added comments which are not required. > > Changes in v3 > -Remove some useless mlocks and send it as another patch. > Also make the necessary change in the current patch associated with > the new patch with commit id 88eba33. Make commit message more > appropriate. > > Changes in v4 > -Write frequency function do not require lock so move it inside > the function to where it is required to protect. > > Changes in v5 > -Remove goto statement and make the code to return -EINVAL there > itself. > > drivers/staging/iio/meter/ade7758.h | 2 +- > drivers/staging/iio/meter/ade7758_core.c | 52 +++++++++++++++++++++++------ > --- > 2 files changed, 39 insertions(+), 15 deletions(-) > > diff --git a/drivers/staging/iio/meter/ade7758.h > b/drivers/staging/iio/meter/ade7758.h > index 6ae78d8..2de81b5 100644 > --- a/drivers/staging/iio/meter/ade7758.h > +++ b/drivers/staging/iio/meter/ade7758.h > @@ -111,7 +111,7 @@ > * @trig: data ready trigger registered with iio > * @tx: transmit buffer > * @rx: receive buffer > - * @buf_lock: mutex to protect tx and rx > + * @buf_lock: mutex to protect tx, rx, read and write > frequency > **/ > struct ade7758_state { > struct spi_device *us; > diff --git a/drivers/staging/iio/meter/ade7758_core.c > b/drivers/staging/iio/meter/ade7758_core.c > index 227dbfc..dfe8e97 100644 > --- a/drivers/staging/iio/meter/ade7758_core.c > +++ b/drivers/staging/iio/meter/ade7758_core.c > @@ -24,17 +24,25 @@ > #include "meter.h" > #include "ade7758.h" > > -int ade7758_spi_write_reg_8(struct device *dev, u8 reg_address, u8 val) > +static int __ade7758_spi_write_reg_8(struct device *dev, u8 reg_address, u8 > val) > { > - int ret; > struct iio_dev *indio_dev = dev_to_iio_dev(dev); > struct ade7758_state *st = iio_priv(indio_dev); > > - mutex_lock(&st->buf_lock); > st->tx[0] = ADE7758_WRITE_REG(reg_address); > st->tx[1] = val; > > - ret = spi_write(st->us, st->tx, 2); > + return spi_write(st->us, st->tx, 2); > +} > + > +int ade7758_spi_write_reg_8(struct device *dev, u8 reg_address, u8 val) > +{ > + int ret; > + struct iio_dev *indio_dev = dev_to_iio_dev(dev); > + struct ade7758_state *st = iio_priv(indio_dev); > + > + mutex_lock(&st->buf_lock); > + ret = __ade7758_spi_write_reg_8(dev, reg_address, val); > mutex_unlock(&st->buf_lock); > > return ret; > @@ -91,7 +99,7 @@ static int ade7758_spi_write_reg_24(struct device *dev, u8 > reg_address, > return ret; > } > > -int ade7758_spi_read_reg_8(struct device *dev, u8 reg_address, u8 *val) > +static int __ade7758_spi_read_reg_8(struct device *dev, u8 reg_address, u8 > *val) > { > struct iio_dev *indio_dev = dev_to_iio_dev(dev); > struct ade7758_state *st = iio_priv(indio_dev); > @@ -111,7 +119,6 @@ int ade7758_spi_read_reg_8(struct device *dev, u8 > reg_address, u8 *val) > }, > }; > > - mutex_lock(&st->buf_lock); > st->tx[0] = ADE7758_READ_REG(reg_address); > st->tx[1] = 0; > > @@ -124,7 +131,19 @@ int ade7758_spi_read_reg_8(struct device *dev, u8 > reg_address, u8 *val) > *val = st->rx[0]; > > error_ret: > + return ret; > +} > + > +int ade7758_spi_read_reg_8(struct device *dev, u8 reg_address, u8 *val) > +{ > + struct iio_dev *indio_dev = dev_to_iio_dev(dev); > + struct ade7758_state *st = iio_priv(indio_dev); > + int ret; > + > + mutex_lock(&st->buf_lock); > + ret = __ade7758_spi_read_reg_8(dev, reg_address, val); > mutex_unlock(&st->buf_lock); > + > return ret; > } > > @@ -480,10 +499,12 @@ static int ade7758_read_samp_freq(struct device *dev, > int *val) > return 0; > } > > -static int ade7758_write_samp_freq(struct device *dev, int val) > +static int ade7758_write_samp_freq(struct iio_dev *indio_dev, int val) Maybe keep the declaration the same. The same construct for accessing indio_dev could be used as above. So: "struct iio_dev *indio_dev = dev_to_iio_dev(dev);" > { > int ret; > u8 reg, t; > + struct ade7758_state *st = iio_priv(indio_dev); > + struct device *dev = &indio_dev->dev; > > switch (val) { > case 26040: > @@ -499,20 +520,23 @@ static int ade7758_write_samp_freq(struct device *dev, > int val) > t = 3; > break; > default: > - ret = -EINVAL; > - goto out; > + return -EINVAL; > } > > - ret = ade7758_spi_read_reg_8(dev, ADE7758_WAVMODE, ®); > + mutex_lock(&st->buf_lock); > + > + ret = __ade7758_spi_read_reg_8(dev, ADE7758_WAVMODE, ®); > if (ret) > goto out; > > reg &= ~(5 << 3); > reg |= t << 5; > > - ret = ade7758_spi_write_reg_8(dev, ADE7758_WAVMODE, reg); > + ret = __ade7758_spi_write_reg_8(dev, ADE7758_WAVMODE, reg); > > out: > + mutex_unlock(&st->buf_lock); > + > return ret; > } > > @@ -545,9 +569,9 @@ static int ade7758_write_raw(struct iio_dev *indio_dev, > case IIO_CHAN_INFO_SAMP_FREQ: > if (val2) > return -EINVAL; > - mutex_lock(&indio_dev->mlock); > - ret = ade7758_write_samp_freq(&indio_dev->dev, val); > - mutex_unlock(&indio_dev->mlock); > + > + ret = ade7758_write_samp_freq(indio_dev, val); > + > return ret; > default: > return -EINVAL;
diff --git a/drivers/staging/iio/meter/ade7758.h b/drivers/staging/iio/meter/ade7758.h index 6ae78d8..2de81b5 100644 --- a/drivers/staging/iio/meter/ade7758.h +++ b/drivers/staging/iio/meter/ade7758.h @@ -111,7 +111,7 @@ * @trig: data ready trigger registered with iio * @tx: transmit buffer * @rx: receive buffer - * @buf_lock: mutex to protect tx and rx + * @buf_lock: mutex to protect tx, rx, read and write frequency **/ struct ade7758_state { struct spi_device *us; diff --git a/drivers/staging/iio/meter/ade7758_core.c b/drivers/staging/iio/meter/ade7758_core.c index 227dbfc..dfe8e97 100644 --- a/drivers/staging/iio/meter/ade7758_core.c +++ b/drivers/staging/iio/meter/ade7758_core.c @@ -24,17 +24,25 @@ #include "meter.h" #include "ade7758.h" -int ade7758_spi_write_reg_8(struct device *dev, u8 reg_address, u8 val) +static int __ade7758_spi_write_reg_8(struct device *dev, u8 reg_address, u8 val) { - int ret; struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct ade7758_state *st = iio_priv(indio_dev); - mutex_lock(&st->buf_lock); st->tx[0] = ADE7758_WRITE_REG(reg_address); st->tx[1] = val; - ret = spi_write(st->us, st->tx, 2); + return spi_write(st->us, st->tx, 2); +} + +int ade7758_spi_write_reg_8(struct device *dev, u8 reg_address, u8 val) +{ + int ret; + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct ade7758_state *st = iio_priv(indio_dev); + + mutex_lock(&st->buf_lock); + ret = __ade7758_spi_write_reg_8(dev, reg_address, val); mutex_unlock(&st->buf_lock); return ret; @@ -91,7 +99,7 @@ static int ade7758_spi_write_reg_24(struct device *dev, u8 reg_address, return ret; } -int ade7758_spi_read_reg_8(struct device *dev, u8 reg_address, u8 *val) +static int __ade7758_spi_read_reg_8(struct device *dev, u8 reg_address, u8 *val) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct ade7758_state *st = iio_priv(indio_dev); @@ -111,7 +119,6 @@ int ade7758_spi_read_reg_8(struct device *dev, u8 reg_address, u8 *val) }, }; - mutex_lock(&st->buf_lock); st->tx[0] = ADE7758_READ_REG(reg_address); st->tx[1] = 0; @@ -124,7 +131,19 @@ int ade7758_spi_read_reg_8(struct device *dev, u8 reg_address, u8 *val) *val = st->rx[0]; error_ret: + return ret; +} + +int ade7758_spi_read_reg_8(struct device *dev, u8 reg_address, u8 *val) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct ade7758_state *st = iio_priv(indio_dev); + int ret; + + mutex_lock(&st->buf_lock); + ret = __ade7758_spi_read_reg_8(dev, reg_address, val); mutex_unlock(&st->buf_lock); + return ret; } @@ -480,10 +499,12 @@ static int ade7758_read_samp_freq(struct device *dev, int *val) return 0; } -static int ade7758_write_samp_freq(struct device *dev, int val) +static int ade7758_write_samp_freq(struct iio_dev *indio_dev, int val) { int ret; u8 reg, t; + struct ade7758_state *st = iio_priv(indio_dev); + struct device *dev = &indio_dev->dev; switch (val) { case 26040: @@ -499,20 +520,23 @@ static int ade7758_write_samp_freq(struct device *dev, int val) t = 3; break; default: - ret = -EINVAL; - goto out; + return -EINVAL; } - ret = ade7758_spi_read_reg_8(dev, ADE7758_WAVMODE, ®); + mutex_lock(&st->buf_lock); + + ret = __ade7758_spi_read_reg_8(dev, ADE7758_WAVMODE, ®); if (ret) goto out; reg &= ~(5 << 3); reg |= t << 5; - ret = ade7758_spi_write_reg_8(dev, ADE7758_WAVMODE, reg); + ret = __ade7758_spi_write_reg_8(dev, ADE7758_WAVMODE, reg); out: + mutex_unlock(&st->buf_lock); + return ret; } @@ -545,9 +569,9 @@ static int ade7758_write_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_SAMP_FREQ: if (val2) return -EINVAL; - mutex_lock(&indio_dev->mlock); - ret = ade7758_write_samp_freq(&indio_dev->dev, val); - mutex_unlock(&indio_dev->mlock); + + ret = ade7758_write_samp_freq(indio_dev, val); + return ret; default: return -EINVAL;
iio_dev->mlock is to be used only by the IIO core for protecting device mode changes between INDIO_DIRECT and INDIO_BUFFER. This patch replaces the use of mlock with the already established buf_lock mutex. Introducing 'unlocked' forms of read and write registers. The read/write frequency functions now require buf_lock to be held. That's not obvious so avoid this but moving the locking inside the functions where it is then clear that they are taking the unlocked forms of the register read/write. It isn't readily apparent that write frequency function requires the locks to be taken, so move it inside the function to where it is required to protect. Signed-off-by: Shreeya Patel <shreeya.patel23498@gmail.com> --- Changes in v2 -Add static keyword to newly introduced functions and remove some added comments which are not required. Changes in v3 -Remove some useless mlocks and send it as another patch. Also make the necessary change in the current patch associated with the new patch with commit id 88eba33. Make commit message more appropriate. Changes in v4 -Write frequency function do not require lock so move it inside the function to where it is required to protect. Changes in v5 -Remove goto statement and make the code to return -EINVAL there itself. drivers/staging/iio/meter/ade7758.h | 2 +- drivers/staging/iio/meter/ade7758_core.c | 52 +++++++++++++++++++++++--------- 2 files changed, 39 insertions(+), 15 deletions(-)