diff mbox series

[v4,1/2] iio: adc: ti-ads7950: Fix improper use of mlock

Message ID 1551392209-20004-2-git-send-email-justinpopo6@gmail.com (mailing list archive)
State New, archived
Headers show
Series iio: adc: ads7950: add gpio support | expand

Commit Message

Justin Chen Feb. 28, 2019, 10:16 p.m. UTC 
From: Justin Chen <justinpopo6@gmail.com>

Indio->mlock is used for protecting the different iio device modes.
It is currently not being used in this way. Replace the lock with
an internal lock specifically used for protecting the SPI transfer
buffer.

Signed-off-by: Justin Chen <justinpopo6@gmail.com>
---
 drivers/iio/adc/ti-ads7950.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

Comments

Jonathan Cameron March 2, 2019, 6:53 p.m. UTC | #1 
On Thu, 28 Feb 2019 14:16:48 -0800
justinpopo6@gmail.com wrote:

> From: Justin Chen <justinpopo6@gmail.com>
> 
> Indio->mlock is used for protecting the different iio device modes.
> It is currently not being used in this way. Replace the lock with
> an internal lock specifically used for protecting the SPI transfer
> buffer.
> 
> Signed-off-by: Justin Chen <justinpopo6@gmail.com>

Great, thanks for doing this.

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/ti-ads7950.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c
> index 0ad6359..1e47bef 100644
> --- a/drivers/iio/adc/ti-ads7950.c
> +++ b/drivers/iio/adc/ti-ads7950.c
> @@ -56,6 +56,9 @@ struct ti_ads7950_state {
>  	struct spi_message	ring_msg;
>  	struct spi_message	scan_single_msg;
>  
> +	/* Lock to protect the spi xfer buffers */
> +	struct mutex		slock;
> +
>  	struct regulator	*reg;
>  	unsigned int		vref_mv;
>  
> @@ -268,6 +271,7 @@ static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p)
>  	struct ti_ads7950_state *st = iio_priv(indio_dev);
>  	int ret;
>  
> +	mutex_lock(&st->slock);
>  	ret = spi_sync(st->spi, &st->ring_msg);
>  	if (ret < 0)
>  		goto out;
> @@ -276,6 +280,7 @@ static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p)
>  					   iio_get_time_ns(indio_dev));
>  
>  out:
> +	mutex_unlock(&st->slock);
>  	iio_trigger_notify_done(indio_dev->trig);
>  
>  	return IRQ_HANDLED;
> @@ -286,7 +291,7 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
>  	struct ti_ads7950_state *st = iio_priv(indio_dev);
>  	int ret, cmd;
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(&st->slock);
>  
>  	cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings;
>  	st->single_tx = cmd;
> @@ -298,7 +303,7 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
>  	ret = st->single_rx;
>  
>  out:
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(&st->slock);
>  
>  	return ret;
>  }
> @@ -432,16 +437,19 @@ static int ti_ads7950_probe(struct spi_device *spi)
>  	if (ACPI_COMPANION(&spi->dev))
>  		st->vref_mv = TI_ADS7950_VA_MV_ACPI_DEFAULT;
>  
> +	mutex_init(&st->slock);
> +
>  	st->reg = devm_regulator_get(&spi->dev, "vref");
>  	if (IS_ERR(st->reg)) {
>  		dev_err(&spi->dev, "Failed get get regulator \"vref\"\n");
> -		return PTR_ERR(st->reg);
> +		ret = PTR_ERR(st->reg);
> +		goto error_destroy_mutex;
>  	}
>  
>  	ret = regulator_enable(st->reg);
>  	if (ret) {
>  		dev_err(&spi->dev, "Failed to enable regulator \"vref\"\n");
> -		return ret;
> +		goto error_destroy_mutex;
>  	}
>  
>  	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> @@ -463,6 +471,8 @@ static int ti_ads7950_probe(struct spi_device *spi)
>  	iio_triggered_buffer_cleanup(indio_dev);
>  error_disable_reg:
>  	regulator_disable(st->reg);
> +error_destroy_mutex:
> +	mutex_destroy(&st->slock);
>  
>  	return ret;
>  }
> @@ -475,6 +485,7 @@ static int ti_ads7950_remove(struct spi_device *spi)
>  	iio_device_unregister(indio_dev);
>  	iio_triggered_buffer_cleanup(indio_dev);
>  	regulator_disable(st->reg);
> +	mutex_destroy(&st->slock);
>  
>  	return 0;
>  }
diff mbox series

Patch

diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c
index 0ad6359..1e47bef 100644
--- a/drivers/iio/adc/ti-ads7950.c
+++ b/drivers/iio/adc/ti-ads7950.c
@@ -56,6 +56,9 @@  struct ti_ads7950_state {
 	struct spi_message	ring_msg;
 	struct spi_message	scan_single_msg;
 
+	/* Lock to protect the spi xfer buffers */
+	struct mutex		slock;
+
 	struct regulator	*reg;
 	unsigned int		vref_mv;
 
@@ -268,6 +271,7 @@  static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p)
 	struct ti_ads7950_state *st = iio_priv(indio_dev);
 	int ret;
 
+	mutex_lock(&st->slock);
 	ret = spi_sync(st->spi, &st->ring_msg);
 	if (ret < 0)
 		goto out;
@@ -276,6 +280,7 @@  static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p)
 					   iio_get_time_ns(indio_dev));
 
 out:
+	mutex_unlock(&st->slock);
 	iio_trigger_notify_done(indio_dev->trig);
 
 	return IRQ_HANDLED;
@@ -286,7 +291,7 @@  static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
 	struct ti_ads7950_state *st = iio_priv(indio_dev);
 	int ret, cmd;
 
-	mutex_lock(&indio_dev->mlock);
+	mutex_lock(&st->slock);
 
 	cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings;
 	st->single_tx = cmd;
@@ -298,7 +303,7 @@  static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
 	ret = st->single_rx;
 
 out:
-	mutex_unlock(&indio_dev->mlock);
+	mutex_unlock(&st->slock);
 
 	return ret;
 }
@@ -432,16 +437,19 @@  static int ti_ads7950_probe(struct spi_device *spi)
 	if (ACPI_COMPANION(&spi->dev))
 		st->vref_mv = TI_ADS7950_VA_MV_ACPI_DEFAULT;
 
+	mutex_init(&st->slock);
+
 	st->reg = devm_regulator_get(&spi->dev, "vref");
 	if (IS_ERR(st->reg)) {
 		dev_err(&spi->dev, "Failed get get regulator \"vref\"\n");
-		return PTR_ERR(st->reg);
+		ret = PTR_ERR(st->reg);
+		goto error_destroy_mutex;
 	}
 
 	ret = regulator_enable(st->reg);
 	if (ret) {
 		dev_err(&spi->dev, "Failed to enable regulator \"vref\"\n");
-		return ret;
+		goto error_destroy_mutex;
 	}
 
 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
@@ -463,6 +471,8 @@  static int ti_ads7950_probe(struct spi_device *spi)
 	iio_triggered_buffer_cleanup(indio_dev);
 error_disable_reg:
 	regulator_disable(st->reg);
+error_destroy_mutex:
+	mutex_destroy(&st->slock);
 
 	return ret;
 }
@@ -475,6 +485,7 @@  static int ti_ads7950_remove(struct spi_device *spi)
 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);
 	regulator_disable(st->reg);
+	mutex_destroy(&st->slock);
 
 	return 0;
 }