[PATCH 3.14 22/43] iio: inv_mpu6050: Clear timestamps fifo while resetting hardware fifo

Greg Kroah-Hartman
2015-04-17T13:32:22Z

From: Viorel Suman <viorel.suman@gmail.com>

commit 4dac0a8eefd55bb1f157d1a5a084531334a2d74c upstream.

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@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -25,6 +25,16 @@
#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;
@@ -51,6 +61,10 @@ int inv_reset_fifo(struct iio_dev *indio
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) {
@@ -84,16 +98,6 @@ 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.
*/
@@ -185,7 +189,6 @@ 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);