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* [PATCH] iio: imu: inv_mpu6050: check for temp_fifo_enable
@ 2020-08-09 15:59 trix
  2020-08-10  8:02 ` Andy Shevchenko
  0 siblings, 1 reply; 4+ messages in thread
From: trix @ 2020-08-09 15:59 UTC (permalink / raw)
  To: jic23, knaack.h, lars, pmeerw, jmaneyrol, mirq-linux, lee.jones
  Cc: linux-iio, linux-kernel, Tom Rix

From: Tom Rix <trix@redhat.com>

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@redhat.com>
---
 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


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2020-09-13 10:22 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-09 15:59 [PATCH] iio: imu: inv_mpu6050: check for temp_fifo_enable trix
2020-08-10  8:02 ` Andy Shevchenko
2020-08-13  8:04   ` Jean-Baptiste Maneyrol
2020-08-16  8:58     ` Jonathan Cameron

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