When an end-of-conversion interrupt is received after performing a single-shot reading of the light sensor, the driver was waking up the result ready queue before checking opt->ok_to_ignore_lock to determine if it should unlock the mutex. The problem occurred in the case where the other thread woke up and changed the value of opt->ok_to_ignore_lock to false prior to the interrupt thread performing its read of the variable. In this case, the mutex would be unlocked twice. Signed-off-by: David Frey <dpfrey@xxxxxxxxx> --- drivers/iio/light/opt3001.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/iio/light/opt3001.c b/drivers/iio/light/opt3001.c index e666879007d2..92004a2563ea 100644 --- a/drivers/iio/light/opt3001.c +++ b/drivers/iio/light/opt3001.c @@ -686,6 +686,7 @@ static irqreturn_t opt3001_irq(int irq, void *_iio) struct iio_dev *iio = _iio; struct opt3001 *opt = iio_priv(iio); int ret; + bool wake_result_ready_queue = false; if (!opt->ok_to_ignore_lock) mutex_lock(&opt->lock); @@ -720,13 +721,16 @@ static irqreturn_t opt3001_irq(int irq, void *_iio) } opt->result = ret; opt->result_ready = true; - wake_up(&opt->result_ready_queue); + wake_result_ready_queue = true; } out: if (!opt->ok_to_ignore_lock) mutex_unlock(&opt->lock); + if (wake_result_ready_queue) + wake_up(&opt->result_ready_queue); + return IRQ_HANDLED; } -- 2.23.0
