On Mon, 3 Jul 2023 15:19:52 +0000 Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@xxxxxxx> 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@xxxxxxx> > Sent: Friday, June 23, 2023 10:29 > To: jic23@xxxxxxxxxx <jic23@xxxxxxxxxx> > Cc: lars@xxxxxxxxxx <lars@xxxxxxxxxx>; linux-iio@xxxxxxxxxxxxxxx <linux-iio@xxxxxxxxxxxxxxx>; Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@xxxxxxx> > Subject: [PATCH] iio: imu: inv_mpu6050: read the full fifo when processing data > > From: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@xxxxxxx> > > 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@xxxxxxx> > --- > 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, ®val); > 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:
