[PATCH 2/4] iio: pressure: mpl3115: clean up interrupt handling and locking

[SeungJu Cheon <suunj1331@gmail.com>]

Return IRQ_NONE instead of IRQ_HANDLED when reading
INT_SOURCE fails.

On shared interrupt lines, returning IRQ_HANDLED after a
failed register read may prevent other handlers from being
invoked.

Switch the trigger handler from explicit mutex_lock/unlock
to scoped_guard() for consistency with the locking style
used elsewhere in the driver.

Move mpl3115_config_interrupt() above the interrupt handler
in preparation for the FIFO support added in a subsequent
patch.

No functional change intended.

Signed-off-by: SeungJu Cheon <suunj1331@gmail.com>
---
 drivers/iio/pressure/mpl3115.c | 59 +++++++++++++++++-----------------
 1 file changed, 29 insertions(+), 30 deletions(-)

diff --git a/drivers/iio/pressure/mpl3115.c b/drivers/iio/pressure/mpl3115.c
index befb6d48efa9..52a3d0d59769 100644
--- a/drivers/iio/pressure/mpl3115.c
+++ b/drivers/iio/pressure/mpl3115.c
@@ -308,9 +308,8 @@ static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
 	u8 buffer[16] __aligned(8) = { };
 	int ret;
 
-	mutex_lock(&data->lock);
-	ret = mpl3115_fill_trig_buffer(indio_dev, buffer);
-	mutex_unlock(&data->lock);
+	scoped_guard(mutex, &data->lock)
+		ret = mpl3115_fill_trig_buffer(indio_dev, buffer);
 	if (ret)
 		goto done;
 
@@ -322,6 +321,32 @@ static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
 	return IRQ_HANDLED;
 }
 
+static int mpl3115_config_interrupt(struct mpl3115_data *data,
+				    u8 ctrl_reg1, u8 ctrl_reg4)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
+					ctrl_reg1);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG4,
+					ctrl_reg4);
+	if (ret < 0)
+		goto reg1_cleanup;
+
+	data->ctrl_reg1 = ctrl_reg1;
+	data->ctrl_reg4 = ctrl_reg4;
+
+	return 0;
+
+reg1_cleanup:
+	i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
+				  data->ctrl_reg1);
+	return ret;
+}
+
 static const struct iio_event_spec mpl3115_temp_press_event[] = {
 	{
 		.type = IIO_EV_TYPE_THRESH,
@@ -381,7 +406,7 @@ static irqreturn_t mpl3115_interrupt_handler(int irq, void *private)
 
 	ret = i2c_smbus_read_byte_data(data->client, MPL3115_INT_SOURCE);
 	if (ret < 0)
-		return IRQ_HANDLED;
+		return IRQ_NONE;
 
 	if (!(ret & (MPL3115_INT_SRC_TTH | MPL3115_INT_SRC_PTH |
 		     MPL3115_INT_SRC_DRDY)))
@@ -420,32 +445,6 @@ static irqreturn_t mpl3115_interrupt_handler(int irq, void *private)
 	return IRQ_HANDLED;
 }
 
-static int mpl3115_config_interrupt(struct mpl3115_data *data,
-				    u8 ctrl_reg1, u8 ctrl_reg4)
-{
-	int ret;
-
-	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
-					ctrl_reg1);
-	if (ret < 0)
-		return ret;
-
-	ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG4,
-					ctrl_reg4);
-	if (ret < 0)
-		goto reg1_cleanup;
-
-	data->ctrl_reg1 = ctrl_reg1;
-	data->ctrl_reg4 = ctrl_reg4;
-
-	return 0;
-
-reg1_cleanup:
-	i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
-				  data->ctrl_reg1);
-	return ret;
-}
-
 static int mpl3115_set_trigger_state(struct iio_trigger *trig, bool state)
 {
 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
-- 
2.52.0