staging: iio: ad7152: Fix deadlock in ad7152_write_raw_samp_freq()

ad7152_write_raw_samp_freq() is called by ad7152_write_raw() with
chip->state_lock held. So, there is unavoidable deadlock when
ad7152_write_raw_samp_freq() locks the mutex itself.

The patch removes unneeded locking.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: 6572389bcc ("staging: iio: cdc: ad7152: Implement
IIO_CHAN_INFO_SAMP_FREQ attribute")
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Alexey Khoroshilov 2017-05-27 01:53:04 +03:00 committed by Jonathan Cameron
parent 3d51b95626
commit 95264c8c6a
1 changed files with 1 additions and 5 deletions

View File

@ -231,16 +231,12 @@ static int ad7152_write_raw_samp_freq(struct device *dev, int val)
if (i >= ARRAY_SIZE(ad7152_filter_rate_table))
i = ARRAY_SIZE(ad7152_filter_rate_table) - 1;
mutex_lock(&chip->state_lock);
ret = i2c_smbus_write_byte_data(chip->client,
AD7152_REG_CFG2, AD7152_CFG2_OSR(i));
if (ret < 0) {
mutex_unlock(&chip->state_lock);
if (ret < 0)
return ret;
}
chip->filter_rate_setup = i;
mutex_unlock(&chip->state_lock);
return ret;
}