[PATCH v2] iio: inv_mpu6050: Clear timestamps fifo while resetting hardware fifo

From: Viorel Suman
Date: Wed Feb 18 2015 - 13:06:12 EST


A hardware fifo reset always imply an invalidation of the
existing timestamps, so we'll clear timestamps fifo on
successfull hardware fifo reset.

Signed-off-by: Viorel Suman <viorel.suman@xxxxxxxxx>
---
v2: Addressed Jonathan's comment regarding the subject prefix.

drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
index 0cd306a..ba27e27 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -24,6 +24,16 @@
#include <linux/poll.h>
#include "inv_mpu_iio.h"

+static void inv_clear_kfifo(struct inv_mpu6050_state *st)
+{
+ unsigned long flags;
+
+ /* take the spin lock sem to avoid interrupt kick in */
+ spin_lock_irqsave(&st->time_stamp_lock, flags);
+ kfifo_reset(&st->timestamps);
+ spin_unlock_irqrestore(&st->time_stamp_lock, flags);
+}
+
int inv_reset_fifo(struct iio_dev *indio_dev)
{
int result;
@@ -50,6 +60,10 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
INV_MPU6050_BIT_FIFO_RST);
if (result)
goto reset_fifo_fail;
+
+ /* clear timestamps fifo */
+ inv_clear_kfifo(st);
+
/* enable interrupt */
if (st->chip_config.accl_fifo_enable ||
st->chip_config.gyro_fifo_enable) {
@@ -83,16 +97,6 @@ reset_fifo_fail:
return result;
}

-static void inv_clear_kfifo(struct inv_mpu6050_state *st)
-{
- unsigned long flags;
-
- /* take the spin lock sem to avoid interrupt kick in */
- spin_lock_irqsave(&st->time_stamp_lock, flags);
- kfifo_reset(&st->timestamps);
- spin_unlock_irqrestore(&st->time_stamp_lock, flags);
-}
-
/**
* inv_mpu6050_irq_handler() - Cache a timestamp at each data ready interrupt.
*/
@@ -184,7 +188,6 @@ end_session:
flush_fifo:
/* Flush HW and SW FIFOs. */
inv_reset_fifo(indio_dev);
- inv_clear_kfifo(st);
mutex_unlock(&indio_dev->mlock);
iio_trigger_notify_done(indio_dev->trig);

--
2.3.0

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