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staging: iio: meter: Replace mlock with driver private buf_lock

PATCH In review Arushi Singhal 2 participants 2 messages Mar 31, 2017 – Apr 2, 2017

Subsystems (4)
Staging IIO Analog Devices IIO drivers Staging - industrial io
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Arushi Singhal

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#0 lore raw

PATCH 1/1 staging: iio: meter: Replace mlock with driver private buf_lock

The driver needs to insure atomicity during frequency changes of bus and device. The iiodev->mlock as used was not doing that. Replace it with the drivers existing buffer lock and execute spi_write directly.

Signed-off-by Arushi Singhal <[email protected]>
---
 drivers/staging/iio/meter/ade7759.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
drivers/staging/iio/meter/ade7759.c +6 -3
index 0b65f1847510..a5ee4501d30a 100644
@@ -429,7 +429,7 @@ static ssize_t ade7759_write_frequency(struct device *dev,
 	if (!val)
 		return -EINVAL;
 
-	mutex_lock(&indio_dev->mlock);
+	mutex_lock(&st->buf_lock);
 
 	t = 27900 / val;
 	if (t > 0)

@@ -447,10 +447,13 @@ static ssize_t ade7759_write_frequency(struct device *dev,
 	reg &= ~(3 << 13);
 	reg |= t << 13;
 
-	ret = ade7759_spi_write_reg_16(dev, ADE7759_MODE, reg);
+	st->tx[0] = ADE7759_WRITE_REG(ADE7759_MODE);
+	st->tx[1] = reg;
+
+	ret = spi_write(st->us, st->tx, 2);
 
 out:
-	mutex_unlock(&indio_dev->mlock);
+	mutex_unlock(&st->buf_lock);
 
 	return ret ? ret : len;
 }
Signature · 1 line
2.11.0
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#1 lore raw
Quoted 6 lines · Arushi Singhal

The driver needs to insure atomicity during frequency changes of bus and device. The iiodev->mlock as used was not doing that. Replace it with the drivers existing buffer lock and execute spi_write directly.

Signed-off-by Arushi Singhal <[email protected]>

Firstly please put the driver name in the title when a patch only effects one driver.

Secondly, please see final version of Gargi Sharma's patch for the ade7754.

As with that one, the basic principle is fine, but I didn't like the V2 version which did the local copy of spi_write as you have here.

Introduced an unlocked version of the ade7759_spi_write_reg_16 function and call it both from ade7759_spi_write_reg_16 and directly here.

Puts the _WRITE_REG magic all in one place.

Otherwise, looks good!

Jonathan

Quoted 34 lines
---
 drivers/staging/iio/meter/ade7759.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
drivers/staging/iio/meter/ade7759.c +6 -3
index 0b65f1847510..a5ee4501d30a 100644
@@ -429,7 +429,7 @@ static ssize_t ade7759_write_frequency(struct device *dev,
 	if (!val)
 		return -EINVAL;
 
-	mutex_lock(&indio_dev->mlock);
+	mutex_lock(&st->buf_lock);
 
 	t = 27900 / val;
 	if (t > 0)

@@ -447,10 +447,13 @@ static ssize_t ade7759_write_frequency(struct device *dev,
 	reg &= ~(3 << 13);
 	reg |= t << 13;
 
-	ret = ade7759_spi_write_reg_16(dev, ADE7759_MODE, reg);
+	st->tx[0] = ADE7759_WRITE_REG(ADE7759_MODE);
+	st->tx[1] = reg;
+
+	ret = spi_write(st->us, st->tx, 2);
 
 out:
-	mutex_unlock(&indio_dev->mlock);
+	mutex_unlock(&st->buf_lock);
 
 	return ret ? ret : len;
 }