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 <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h
index 9209f47..7512cf7 100644
--- a/drivers/iio/iio_core.h
+++ b/drivers/iio/iio_core.h
@@ -50,6 +50,7 @@
#define iio_buffer_read_first_n_outer_addr (&iio_buffer_read_first_n_outer)
void iio_disable_all_buffers(struct iio_dev *indio_dev);
+void iio_buffer_wakeup_poll(struct iio_dev *indio_dev);
#else
@@ -57,11 +58,13 @@
#define iio_buffer_read_first_n_outer_addr NULL
static inline void iio_disable_all_buffers(struct iio_dev *indio_dev) {}
+static inline void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) {}
#endif
int iio_device_register_eventset(struct iio_dev *indio_dev);
void iio_device_unregister_eventset(struct iio_dev *indio_dev);
+void iio_device_wakeup_eventset(struct iio_dev *indio_dev);
int iio_event_getfd(struct iio_dev *indio_dev);
#endif
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 6c7a9c5..5a46c57 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -20,6 +20,7 @@
#include <linux/cdev.h>
#include <linux/slab.h>
#include <linux/poll.h>
+#include <linux/sched.h>
#include <linux/iio/iio.h>
#include "iio_core.h"
@@ -75,6 +76,21 @@
return 0;
}
+/**
+ * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
+ * @indio_dev: The IIO device
+ *
+ * Wakes up the event waitqueue used for poll(). Should usually
+ * be called when the device is unregistered.
+ */
+void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
+{
+ if (!indio_dev->buffer)
+ return;
+
+ wake_up(&indio_dev->buffer->pollq);
+}
+
void iio_buffer_init(struct iio_buffer *buffer)
{
INIT_LIST_HEAD(&buffer->demux_list);
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index a019a7b..dc24a9b 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -1139,6 +1139,10 @@
iio_disable_all_buffers(indio_dev);
indio_dev->info = NULL;
+
+ iio_device_wakeup_eventset(indio_dev);
+ iio_buffer_wakeup_poll(indio_dev);
+
mutex_unlock(&indio_dev->info_exist_lock);
}
EXPORT_SYMBOL(iio_device_unregister);
diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
index 837d450..d251f30 100644
--- a/drivers/iio/industrialio-event.c
+++ b/drivers/iio/industrialio-event.c
@@ -113,9 +113,14 @@
}
/* 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 @@
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)