4.11-stable review patch. If anyone has any objections, please let me know.
------------------ From: Alexey Khoroshilov <[email protected]> commit 95264c8c6a9040e84edda883dbbe9d193c41f46c upstream. 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 <[email protected]> Fixes: 6572389bcc11 ("staging: iio: cdc: ad7152: Implement IIO_CHAN_INFO_SAMP_FREQ attribute") Acked-by: Lars-Peter Clausen <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/staging/iio/cdc/ad7152.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) --- a/drivers/staging/iio/cdc/ad7152.c +++ b/drivers/staging/iio/cdc/ad7152.c @@ -231,16 +231,12 @@ static int ad7152_write_raw_samp_freq(st 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; }
