linux-kernel - [PATCH 03/10] iio: imu: adis[16480]: group RW into a single lock in adis_enable

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Date:   Thu, 26 Sep 2019 14:18:05 +0300
From:   Alexandru Ardelean <alexandru.ardelean@...log.com>
To:     <linux-iio@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC:     <jic23@...nel.org>,
        Alexandru Ardelean <alexandru.ardelean@...log.com>
Subject: [PATCH 03/10] iio: imu: adis[16480]: group RW into a single lock in adis_enable_irq()

The adis_enable_irq() does a read & a write. This change keeps a lock for
the duration of both operations vs for each op.

The change is also needed in adis16480, since that has it's own
implementation for adis_enable_irq().

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@...log.com>
---
 drivers/iio/imu/adis.c      | 17 +++++++++++------
 drivers/iio/imu/adis16480.c |  4 ++--
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
index 4f3be011c898..dc30f70d36f3 100644
--- a/drivers/iio/imu/adis.c
+++ b/drivers/iio/imu/adis.c
@@ -250,12 +250,16 @@ int adis_enable_irq(struct adis *adis, bool enable)
 	int ret = 0;
 	uint16_t msc;
 
-	if (adis->data->enable_irq)
-		return adis->data->enable_irq(adis, enable);
+	mutex_lock(&adis->state_lock);
+
+	if (adis->data->enable_irq) {
+		ret = adis->data->enable_irq(adis, enable);
+		goto out_unlock;
+	}
 
-	ret = adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
+	ret = __adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
 	if (ret)
-		goto error_ret;
+		goto out_unlock;
 
 	msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH;
 	msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2;
@@ -264,9 +268,10 @@ int adis_enable_irq(struct adis *adis, bool enable)
 	else
 		msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;
 
-	ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);
+	ret = __adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);
 
-error_ret:
+out_unlock:
+	mutex_unlock(&adis->state_lock);
 	return ret;
 }
 EXPORT_SYMBOL(adis_enable_irq);
diff --git a/drivers/iio/imu/adis16480.c b/drivers/iio/imu/adis16480.c
index b99d73887c9f..dc13d8a33612 100644
--- a/drivers/iio/imu/adis16480.c
+++ b/drivers/iio/imu/adis16480.c
@@ -936,14 +936,14 @@ static int adis16480_enable_irq(struct adis *adis, bool enable)
 	uint16_t val;
 	int ret;
 
-	ret = adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, &val);
+	ret = __adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, &val);
 	if (ret < 0)
 		return ret;
 
 	val &= ~ADIS16480_DRDY_EN_MSK;
 	val |= ADIS16480_DRDY_EN(enable);
 
-	return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, val);
+	return __adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, val);
 }
 
 static int adis16480_initial_setup(struct iio_dev *indio_dev)
-- 
2.20.1