diff mbox series

iio: imu: inv_mpu6050: read the full fifo when processing data

Message ID 20230623082924.283967-1-inv.git-commit@tdk.com (mailing list archive)
State Accepted
Headers show
Series iio: imu: inv_mpu6050: read the full fifo when processing data | expand

Commit Message

inv.git-commit@tdk.com June 23, 2023, 8:29 a.m. UTC
From: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>

When processing data read the full fifo data in 1 time. If there
are several samples in the FIFO, it means we are experiencing
system delay. In this case, it is better to read all data with 1
bus access than to add additional latency by doing several ones.

This requires to use a bigger buffer depending on chip FIFO size
and do an additional local data copy before sending. But the cost
is minimal and behavior is still better like this under system
heavy load.

Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
---
 drivers/iio/imu/inv_mpu6050/inv_mpu_core.c |  3 +++
 drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  4 ++--
 drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 19 +++++++++++++------
 3 files changed, 18 insertions(+), 8 deletions(-)

Comments

Jean-Baptiste Maneyrol July 3, 2023, 3:19 p.m. UTC | #1
Hello Jonathan,

any news about this patch?

Thanks for your feedback,
JB


From: INV Git Commit <INV.git-commit@tdk.com>
Sent: Friday, June 23, 2023 10:29
To: jic23@kernel.org <jic23@kernel.org>
Cc: lars@metafoo.de <lars@metafoo.de>; linux-iio@vger.kernel.org <linux-iio@vger.kernel.org>; Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@tdk.com>
Subject: [PATCH] iio: imu: inv_mpu6050: read the full fifo when processing data 
 
From: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>

When processing data read the full fifo data in 1 time. If there
are several samples in the FIFO, it means we are experiencing
system delay. In this case, it is better to read all data with 1
bus access than to add additional latency by doing several ones.

This requires to use a bigger buffer depending on chip FIFO size
and do an additional local data copy before sending. But the cost
is minimal and behavior is still better like this under system
heavy load.

Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
---
 drivers/iio/imu/inv_mpu6050/inv_mpu_core.c |  3 +++
 drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  4 ++--
 drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 19 +++++++++++++------
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index 13086b569b90..29f906c884bd 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -1345,6 +1345,9 @@ static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
         st->reg = hw_info[st->chip_type].reg;
         memcpy(&st->chip_config, hw_info[st->chip_type].config,
                sizeof(st->chip_config));
+       st->data = devm_kzalloc(regmap_get_device(st->map), st->hw->fifo_size, GFP_KERNEL);
+       if (st->data == NULL)
+               return -ENOMEM;
 
         /* check chip self-identification */
         result = regmap_read(st->map, INV_MPU6050_REG_WHOAMI, &regval);
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
index a51d103a57ca..ed5a96e78df0 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -179,7 +179,7 @@ struct inv_mpu6050_hw {
  *  @magn_raw_to_gauss:        coefficient to convert mag raw value to Gauss.
  *  @magn_orient:       magnetometer sensor chip orientation if available.
  *  @suspended_sensors:        sensors mask of sensors turned off for suspend
- *  @data:             dma safe buffer used for bulk reads.
+ *  @data:             read buffer used for bulk reads.
  */
 struct inv_mpu6050_state {
         struct mutex lock;
@@ -203,7 +203,7 @@ struct inv_mpu6050_state {
         s32 magn_raw_to_gauss[3];
         struct iio_mount_matrix magn_orient;
         unsigned int suspended_sensors;
-       u8 data[INV_MPU6050_OUTPUT_DATA_SIZE] __aligned(IIO_DMA_MINALIGN);
+       u8 *data;
 };
 
 /*register and associated bit definition*/
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
index d83f61a99504..66d4ba088e70 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -52,6 +52,7 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
         u16 fifo_count;
         u32 fifo_period;
         s64 timestamp;
+       u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
         int int_status;
         size_t i, nb;
 
@@ -105,24 +106,30 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
                 goto flush_fifo;
         }
 
-       /* compute and process all complete datum */
+       /* compute and process only all complete datum */
         nb = fifo_count / bytes_per_datum;
+       fifo_count = nb * bytes_per_datum;
         /* Each FIFO data contains all sensors, so same number for FIFO and sensor data */
         fifo_period = NSEC_PER_SEC / INV_MPU6050_DIVIDER_TO_FIFO_RATE(st->chip_config.divider);
         inv_sensors_timestamp_interrupt(&st->timestamp, fifo_period, nb, nb, pf->timestamp);
         inv_sensors_timestamp_apply_odr(&st->timestamp, fifo_period, nb, 0);
+
+       /* clear internal data buffer for avoiding kernel data leak */
+       memset(data, 0, sizeof(data));
+
+       /* read all data once and process every samples */
+       result = regmap_noinc_read(st->map, st->reg->fifo_r_w, st->data, fifo_count);
+       if (result)
+               goto flush_fifo;
         for (i = 0; i < nb; ++i) {
-               result = regmap_noinc_read(st->map, st->reg->fifo_r_w,
-                                          st->data, bytes_per_datum);
-               if (result)
-                       goto flush_fifo;
                 /* skip first samples if needed */
                 if (st->skip_samples) {
                         st->skip_samples--;
                         continue;
                 }
+               memcpy(data, &st->data[i * bytes_per_datum], bytes_per_datum);
                 timestamp = inv_sensors_timestamp_pop(&st->timestamp);
-               iio_push_to_buffers_with_timestamp(indio_dev, st->data, timestamp);
+               iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
         }
 
 end_session:
Jonathan Cameron July 5, 2023, 7:58 a.m. UTC | #2
On Mon, 3 Jul 2023 15:19:52 +0000
Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@tdk.com> wrote:

> Hello Jonathan,
> 
> any news about this patch?
> 
> Thanks for your feedback,

LGTM.  I'm traveling however, so I've just been marking stuff that
is ready for queuing up in patchwork. Will send replies when I actually
queue them.

https://patchwork.kernel.org/project/linux-iio/list/

See patches labeled 'queued' which I'm using for this purpose.
Normally I'd just use applied and push the tree out the same
day.

Jonathan

> JB
> 
> 
> From: INV Git Commit <INV.git-commit@tdk.com>
> Sent: Friday, June 23, 2023 10:29
> To: jic23@kernel.org <jic23@kernel.org>
> Cc: lars@metafoo.de <lars@metafoo.de>; linux-iio@vger.kernel.org <linux-iio@vger.kernel.org>; Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@tdk.com>
> Subject: [PATCH] iio: imu: inv_mpu6050: read the full fifo when processing data 
>  
> From: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
> 
> When processing data read the full fifo data in 1 time. If there
> are several samples in the FIFO, it means we are experiencing
> system delay. In this case, it is better to read all data with 1
> bus access than to add additional latency by doing several ones.
> 
> This requires to use a bigger buffer depending on chip FIFO size
> and do an additional local data copy before sending. But the cost
> is minimal and behavior is still better like this under system
> heavy load.
> 
> Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
> ---
>  drivers/iio/imu/inv_mpu6050/inv_mpu_core.c |  3 +++
>  drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  4 ++--
>  drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 19 +++++++++++++------
>  3 files changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> index 13086b569b90..29f906c884bd 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> @@ -1345,6 +1345,9 @@ static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
>          st->reg = hw_info[st->chip_type].reg;
>          memcpy(&st->chip_config, hw_info[st->chip_type].config,
>                 sizeof(st->chip_config));
> +       st->data = devm_kzalloc(regmap_get_device(st->map), st->hw->fifo_size, GFP_KERNEL);
> +       if (st->data == NULL)
> +               return -ENOMEM;
>  
>          /* check chip self-identification */
>          result = regmap_read(st->map, INV_MPU6050_REG_WHOAMI, &regval);
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> index a51d103a57ca..ed5a96e78df0 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> @@ -179,7 +179,7 @@ struct inv_mpu6050_hw {
>   *  @magn_raw_to_gauss:        coefficient to convert mag raw value to Gauss.
>   *  @magn_orient:       magnetometer sensor chip orientation if available.
>   *  @suspended_sensors:        sensors mask of sensors turned off for suspend
> - *  @data:             dma safe buffer used for bulk reads.
> + *  @data:             read buffer used for bulk reads.
>   */
>  struct inv_mpu6050_state {
>          struct mutex lock;
> @@ -203,7 +203,7 @@ struct inv_mpu6050_state {
>          s32 magn_raw_to_gauss[3];
>          struct iio_mount_matrix magn_orient;
>          unsigned int suspended_sensors;
> -       u8 data[INV_MPU6050_OUTPUT_DATA_SIZE] __aligned(IIO_DMA_MINALIGN);
> +       u8 *data;
>  };
>  
>  /*register and associated bit definition*/
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> index d83f61a99504..66d4ba088e70 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> @@ -52,6 +52,7 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
>          u16 fifo_count;
>          u32 fifo_period;
>          s64 timestamp;
> +       u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
>          int int_status;
>          size_t i, nb;
>  
> @@ -105,24 +106,30 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
>                  goto flush_fifo;
>          }
>  
> -       /* compute and process all complete datum */
> +       /* compute and process only all complete datum */
>          nb = fifo_count / bytes_per_datum;
> +       fifo_count = nb * bytes_per_datum;
>          /* Each FIFO data contains all sensors, so same number for FIFO and sensor data */
>          fifo_period = NSEC_PER_SEC / INV_MPU6050_DIVIDER_TO_FIFO_RATE(st->chip_config.divider);
>          inv_sensors_timestamp_interrupt(&st->timestamp, fifo_period, nb, nb, pf->timestamp);
>          inv_sensors_timestamp_apply_odr(&st->timestamp, fifo_period, nb, 0);
> +
> +       /* clear internal data buffer for avoiding kernel data leak */
> +       memset(data, 0, sizeof(data));
> +
> +       /* read all data once and process every samples */
> +       result = regmap_noinc_read(st->map, st->reg->fifo_r_w, st->data, fifo_count);
> +       if (result)
> +               goto flush_fifo;
>          for (i = 0; i < nb; ++i) {
> -               result = regmap_noinc_read(st->map, st->reg->fifo_r_w,
> -                                          st->data, bytes_per_datum);
> -               if (result)
> -                       goto flush_fifo;
>                  /* skip first samples if needed */
>                  if (st->skip_samples) {
>                          st->skip_samples--;
>                          continue;
>                  }
> +               memcpy(data, &st->data[i * bytes_per_datum], bytes_per_datum);
>                  timestamp = inv_sensors_timestamp_pop(&st->timestamp);
> -               iio_push_to_buffers_with_timestamp(indio_dev, st->data, timestamp);
> +               iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
>          }
>  
>  end_session:
Jonathan Cameron July 8, 2023, 2:26 p.m. UTC | #3
On Wed, 5 Jul 2023 15:58:34 +0800
Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:

> On Mon, 3 Jul 2023 15:19:52 +0000
> Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@tdk.com> wrote:
> 
> > Hello Jonathan,
> > 
> > any news about this patch?
> > 
> > Thanks for your feedback,  
> 
> LGTM.  I'm traveling however, so I've just been marking stuff that
> is ready for queuing up in patchwork. Will send replies when I actually
> queue them.
> 
> https://patchwork.kernel.org/project/linux-iio/list/
> 
> See patches labeled 'queued' which I'm using for this purpose.
> Normally I'd just use applied and push the tree out the same
> day.
> 
Back home. Applied to the togreg branch of iio.git.
However, as mid merge window that will only be exposed as testing for 0-day
to poke at until I can rebase on rc1.

Thanks,

Jonathan

> Jonathan
> 
> > JB
> > 
> > 
> > From: INV Git Commit <INV.git-commit@tdk.com>
> > Sent: Friday, June 23, 2023 10:29
> > To: jic23@kernel.org <jic23@kernel.org>
> > Cc: lars@metafoo.de <lars@metafoo.de>; linux-iio@vger.kernel.org <linux-iio@vger.kernel.org>; Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@tdk.com>
> > Subject: [PATCH] iio: imu: inv_mpu6050: read the full fifo when processing data 
> >  
> > From: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
> > 
> > When processing data read the full fifo data in 1 time. If there
> > are several samples in the FIFO, it means we are experiencing
> > system delay. In this case, it is better to read all data with 1
> > bus access than to add additional latency by doing several ones.
> > 
> > This requires to use a bigger buffer depending on chip FIFO size
> > and do an additional local data copy before sending. But the cost
> > is minimal and behavior is still better like this under system
> > heavy load.
> > 
> > Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
> > ---
> >  drivers/iio/imu/inv_mpu6050/inv_mpu_core.c |  3 +++
> >  drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h  |  4 ++--
> >  drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 19 +++++++++++++------
> >  3 files changed, 18 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> > index 13086b569b90..29f906c884bd 100644
> > --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> > +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> > @@ -1345,6 +1345,9 @@ static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
> >          st->reg = hw_info[st->chip_type].reg;
> >          memcpy(&st->chip_config, hw_info[st->chip_type].config,
> >                 sizeof(st->chip_config));
> > +       st->data = devm_kzalloc(regmap_get_device(st->map), st->hw->fifo_size, GFP_KERNEL);
> > +       if (st->data == NULL)
> > +               return -ENOMEM;
> >  
> >          /* check chip self-identification */
> >          result = regmap_read(st->map, INV_MPU6050_REG_WHOAMI, &regval);
> > diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> > index a51d103a57ca..ed5a96e78df0 100644
> > --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> > +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> > @@ -179,7 +179,7 @@ struct inv_mpu6050_hw {
> >   *  @magn_raw_to_gauss:        coefficient to convert mag raw value to Gauss.
> >   *  @magn_orient:       magnetometer sensor chip orientation if available.
> >   *  @suspended_sensors:        sensors mask of sensors turned off for suspend
> > - *  @data:             dma safe buffer used for bulk reads.
> > + *  @data:             read buffer used for bulk reads.
> >   */
> >  struct inv_mpu6050_state {
> >          struct mutex lock;
> > @@ -203,7 +203,7 @@ struct inv_mpu6050_state {
> >          s32 magn_raw_to_gauss[3];
> >          struct iio_mount_matrix magn_orient;
> >          unsigned int suspended_sensors;
> > -       u8 data[INV_MPU6050_OUTPUT_DATA_SIZE] __aligned(IIO_DMA_MINALIGN);
> > +       u8 *data;
> >  };
> >  
> >  /*register and associated bit definition*/
> > diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> > index d83f61a99504..66d4ba088e70 100644
> > --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> > +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> > @@ -52,6 +52,7 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
> >          u16 fifo_count;
> >          u32 fifo_period;
> >          s64 timestamp;
> > +       u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
> >          int int_status;
> >          size_t i, nb;
> >  
> > @@ -105,24 +106,30 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
> >                  goto flush_fifo;
> >          }
> >  
> > -       /* compute and process all complete datum */
> > +       /* compute and process only all complete datum */
> >          nb = fifo_count / bytes_per_datum;
> > +       fifo_count = nb * bytes_per_datum;
> >          /* Each FIFO data contains all sensors, so same number for FIFO and sensor data */
> >          fifo_period = NSEC_PER_SEC / INV_MPU6050_DIVIDER_TO_FIFO_RATE(st->chip_config.divider);
> >          inv_sensors_timestamp_interrupt(&st->timestamp, fifo_period, nb, nb, pf->timestamp);
> >          inv_sensors_timestamp_apply_odr(&st->timestamp, fifo_period, nb, 0);
> > +
> > +       /* clear internal data buffer for avoiding kernel data leak */
> > +       memset(data, 0, sizeof(data));
> > +
> > +       /* read all data once and process every samples */
> > +       result = regmap_noinc_read(st->map, st->reg->fifo_r_w, st->data, fifo_count);
> > +       if (result)
> > +               goto flush_fifo;
> >          for (i = 0; i < nb; ++i) {
> > -               result = regmap_noinc_read(st->map, st->reg->fifo_r_w,
> > -                                          st->data, bytes_per_datum);
> > -               if (result)
> > -                       goto flush_fifo;
> >                  /* skip first samples if needed */
> >                  if (st->skip_samples) {
> >                          st->skip_samples--;
> >                          continue;
> >                  }
> > +               memcpy(data, &st->data[i * bytes_per_datum], bytes_per_datum);
> >                  timestamp = inv_sensors_timestamp_pop(&st->timestamp);
> > -               iio_push_to_buffers_with_timestamp(indio_dev, st->data, timestamp);
> > +               iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
> >          }
> >  
> >  end_session:  
>
diff mbox series

Patch

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index 13086b569b90..29f906c884bd 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -1345,6 +1345,9 @@  static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
 	st->reg = hw_info[st->chip_type].reg;
 	memcpy(&st->chip_config, hw_info[st->chip_type].config,
 	       sizeof(st->chip_config));
+	st->data = devm_kzalloc(regmap_get_device(st->map), st->hw->fifo_size, GFP_KERNEL);
+	if (st->data == NULL)
+		return -ENOMEM;
 
 	/* check chip self-identification */
 	result = regmap_read(st->map, INV_MPU6050_REG_WHOAMI, &regval);
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
index a51d103a57ca..ed5a96e78df0 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -179,7 +179,7 @@  struct inv_mpu6050_hw {
  *  @magn_raw_to_gauss:	coefficient to convert mag raw value to Gauss.
  *  @magn_orient:       magnetometer sensor chip orientation if available.
  *  @suspended_sensors:	sensors mask of sensors turned off for suspend
- *  @data:		dma safe buffer used for bulk reads.
+ *  @data:		read buffer used for bulk reads.
  */
 struct inv_mpu6050_state {
 	struct mutex lock;
@@ -203,7 +203,7 @@  struct inv_mpu6050_state {
 	s32 magn_raw_to_gauss[3];
 	struct iio_mount_matrix magn_orient;
 	unsigned int suspended_sensors;
-	u8 data[INV_MPU6050_OUTPUT_DATA_SIZE] __aligned(IIO_DMA_MINALIGN);
+	u8 *data;
 };
 
 /*register and associated bit definition*/
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
index d83f61a99504..66d4ba088e70 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -52,6 +52,7 @@  irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
 	u16 fifo_count;
 	u32 fifo_period;
 	s64 timestamp;
+	u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
 	int int_status;
 	size_t i, nb;
 
@@ -105,24 +106,30 @@  irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
 		goto flush_fifo;
 	}
 
-	/* compute and process all complete datum */
+	/* compute and process only all complete datum */
 	nb = fifo_count / bytes_per_datum;
+	fifo_count = nb * bytes_per_datum;
 	/* Each FIFO data contains all sensors, so same number for FIFO and sensor data */
 	fifo_period = NSEC_PER_SEC / INV_MPU6050_DIVIDER_TO_FIFO_RATE(st->chip_config.divider);
 	inv_sensors_timestamp_interrupt(&st->timestamp, fifo_period, nb, nb, pf->timestamp);
 	inv_sensors_timestamp_apply_odr(&st->timestamp, fifo_period, nb, 0);
+
+	/* clear internal data buffer for avoiding kernel data leak */
+	memset(data, 0, sizeof(data));
+
+	/* read all data once and process every samples */
+	result = regmap_noinc_read(st->map, st->reg->fifo_r_w, st->data, fifo_count);
+	if (result)
+		goto flush_fifo;
 	for (i = 0; i < nb; ++i) {
-		result = regmap_noinc_read(st->map, st->reg->fifo_r_w,
-					   st->data, bytes_per_datum);
-		if (result)
-			goto flush_fifo;
 		/* skip first samples if needed */
 		if (st->skip_samples) {
 			st->skip_samples--;
 			continue;
 		}
+		memcpy(data, &st->data[i * bytes_per_datum], bytes_per_datum);
 		timestamp = inv_sensors_timestamp_pop(&st->timestamp);
-		iio_push_to_buffers_with_timestamp(indio_dev, st->data, timestamp);
+		iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
 	}
 
 end_session: