Some chips have a fifo overflow bit issue where the bit is always set. The result is that every data is dropped.

Change fifo overflow management by checking fifo count against a maximum value.

Add fifo size in chip hardware set of values.

Fixes: f5057e7b2dba ("iio: imu: inv_mpu6050: better fifo overflow handling") Cc: stable@vger.kernel.org Signed-off-by: Jean-Baptiste Maneyrol jmaneyrol@invensense.com --- drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 8 ++++++++ drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 2 ++ drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 15 ++++++++++++--- 3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c index d80ef468508a..59b1040ee4c7 100644 --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c @@ -96,48 +96,56 @@ static const struct inv_mpu6050_hw hw_info[] = { .name = "MPU6050", .reg = &reg_set_6050, .config = &chip_config_6050, + .fifo_size = 1024, }, { .whoami = INV_MPU6500_WHOAMI_VALUE, .name = "MPU6500", .reg = &reg_set_6500, .config = &chip_config_6050, + .fifo_size = 512, }, { .whoami = INV_MPU6515_WHOAMI_VALUE, .name = "MPU6515", .reg = &reg_set_6500, .config = &chip_config_6050, + .fifo_size = 512, }, { .whoami = INV_MPU6000_WHOAMI_VALUE, .name = "MPU6000", .reg = &reg_set_6050, .config = &chip_config_6050, + .fifo_size = 1024, }, { .whoami = INV_MPU9150_WHOAMI_VALUE, .name = "MPU9150", .reg = &reg_set_6050, .config = &chip_config_6050, + .fifo_size = 1024, }, { .whoami = INV_MPU9250_WHOAMI_VALUE, .name = "MPU9250", .reg = &reg_set_6500, .config = &chip_config_6050, + .fifo_size = 512, }, { .whoami = INV_MPU9255_WHOAMI_VALUE, .name = "MPU9255", .reg = &reg_set_6500, .config = &chip_config_6050, + .fifo_size = 512, }, { .whoami = INV_ICM20608_WHOAMI_VALUE, .name = "ICM20608", .reg = &reg_set_6500, .config = &chip_config_6050, + .fifo_size = 512, }, };

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h index e69a59659dbc..07c6214f3222 100644 --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h @@ -105,12 +105,14 @@ struct inv_mpu6050_chip_config { * @name: name of the chip. * @reg: register map of the chip. * @config: configuration of the chip. + * @fifo_size: size of the FIFO in bytes. */ struct inv_mpu6050_hw { u8 whoami; u8 *name; const struct inv_mpu6050_reg_map *reg; const struct inv_mpu6050_chip_config *config; + size_t fifo_size; };

/* diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c index 548e042f7b5b..4f9c2765aa23 100644 --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c @@ -188,9 +188,6 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p) "failed to ack interrupt\n"); goto flush_fifo; } - /* handle fifo overflow by reseting fifo */ - if (int_status & INV_MPU6050_BIT_FIFO_OVERFLOW_INT) - goto flush_fifo; if (!(int_status & INV_MPU6050_BIT_RAW_DATA_RDY_INT)) { dev_warn(regmap_get_device(st->map), "spurious interrupt with status 0x%x\n", int_status); @@ -216,6 +213,18 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p) if (result) goto end_session; fifo_count = get_unaligned_be16(&data[0]); + + /* + * Handle fifo overflow by resetting fifo. + * Reset if there is only 3 data set free remaining to mitigate + * possible delay between reading fifo count and fifo data. + */ + nb = 3 * bytes_per_datum; + if (fifo_count >= st->hw->fifo_size - nb) { + dev_warn(regmap_get_device(st->map), "fifo overflow reset\n"); + goto flush_fifo; + } + /* compute and process all complete datum */ nb = fifo_count / bytes_per_datum; inv_mpu6050_update_period(st, pf->timestamp, nb);