From d2f0a48f36aea38e0a5c4b439d5d9c96aecabad9 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Fri, 4 Oct 2013 12:07:00 +0100 Subject: iio: Wakeup poll and blocking reads when the device is unregistered Once the device has been unregistered there won't be any new data no matter how long a userspace application waits, so we might as well wake them up and let them know. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- drivers/iio/industrialio-event.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'drivers/iio/industrialio-event.c') diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c index 837d450457dd..d251f30fb739 100644 --- a/drivers/iio/industrialio-event.c +++ b/drivers/iio/industrialio-event.c @@ -113,9 +113,14 @@ static ssize_t iio_event_chrdev_read(struct file *filep, } /* Blocking on device; waiting for something to be there */ ret = wait_event_interruptible_locked_irq(ev_int->wait, - !kfifo_is_empty(&ev_int->det_events)); + !kfifo_is_empty(&ev_int->det_events) || + indio_dev->info == NULL); if (ret) goto error_unlock; + if (indio_dev->info == NULL) { + ret = -ENODEV; + goto error_unlock; + } /* Single access device so no one else can get the data */ } @@ -454,6 +459,20 @@ error_ret: return ret; } +/** + * iio_device_wakeup_eventset - Wakes up the event waitqueue + * @indio_dev: The IIO device + * + * Wakes up the event waitqueue used for poll() and blocking read(). + * Should usually be called when the device is unregistered. + */ +void iio_device_wakeup_eventset(struct iio_dev *indio_dev) +{ + if (indio_dev->event_interface == NULL) + return; + wake_up(&indio_dev->event_interface->wait); +} + void iio_device_unregister_eventset(struct iio_dev *indio_dev) { if (indio_dev->event_interface == NULL) -- cgit v1.2.3