[PATCH] iio: imu: inv_mpu6050: check for temp_fifo_enable

From: trix
Date: Sun Aug 09 2020 - 12:00:36 EST


From: Tom Rix <trix@xxxxxxxxxx>

clang static analysis reports this problem

inv_mpu_ring.c:181:18: warning: Division by zero
nb = fifo_count / bytes_per_datum;
~~~~~~~~~~~^~~~~~~~~~~~~~~~~

This is a false positive.
Dividing by 0 is protected by this check

if (!(st->chip_config.accl_fifo_enable |
st->chip_config.gyro_fifo_enable |
st->chip_config.magn_fifo_enable))
goto end_session;
bytes_per_datum = 0;

But there is another fifo, temp_fifo

if (st->chip_config.temp_fifo_enable)
bytes_per_datum += INV_MPU6050_BYTES_PER_TEMP_SENSOR;

Which would be skipped if it was the only enabled fifo.
So add to the check.

Fixes: 2e4c0a5e2576 ("iio: imu: inv_mpu6050: add fifo temperature data support")

Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
index b533fa2dad0a..5240a400dcb4 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -141,6 +141,7 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)

if (!(st->chip_config.accl_fifo_enable |
st->chip_config.gyro_fifo_enable |
+ st->chip_config.temp_fifo_enable |
st->chip_config.magn_fifo_enable))
goto end_session;
bytes_per_datum = 0;
--
2.18.1