iio: Stop sampling when the device is removed

Make sure to stop sampling when the device is removed, otherwise it will
continue to sample forever.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/iio_core.h

@@ -49,11 +49,15 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
 #define iio_buffer_poll_addr (&iio_buffer_poll)
 #define iio_buffer_read_first_n_outer_addr (&iio_buffer_read_first_n_outer)
 
+void iio_disable_all_buffers(struct iio_dev *indio_dev);
+
 #else
 
 #define iio_buffer_poll_addr NULL
 #define iio_buffer_read_first_n_outer_addr NULL
 
+static inline void iio_disable_all_buffers(struct iio_dev *indio_dev) {}
+
 #endif
 
 int iio_device_register_eventset(struct iio_dev *indio_dev);

drivers/iio/industrialio-buffer.c

@@ -460,6 +460,25 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev, const long *mask,
 	return bytes;
 }
 
+void iio_disable_all_buffers(struct iio_dev *indio_dev)
+{
+	struct iio_buffer *buffer, *_buffer;
+
+	if (list_empty(&indio_dev->buffer_list))
+		return;
+
+	if (indio_dev->setup_ops->predisable)
+		indio_dev->setup_ops->predisable(indio_dev);
+
+	list_for_each_entry_safe(buffer, _buffer,
+			&indio_dev->buffer_list, buffer_list)
+		list_del_init(&buffer->buffer_list);
+
+	indio_dev->currentmode = INDIO_DIRECT_MODE;
+	if (indio_dev->setup_ops->postdisable)
+		indio_dev->setup_ops->postdisable(indio_dev);
+}
+
 int iio_update_buffers(struct iio_dev *indio_dev,
 		       struct iio_buffer *insert_buffer,
 		       struct iio_buffer *remove_buffer)

drivers/iio/industrialio-core.c

@@ -1078,9 +1078,13 @@ EXPORT_SYMBOL(iio_device_register);
 void iio_device_unregister(struct iio_dev *indio_dev)
 {
 	mutex_lock(&indio_dev->info_exist_lock);
+
+	device_del(&indio_dev->dev);
+
+	iio_disable_all_buffers(indio_dev);
+
 	indio_dev->info = NULL;
 	mutex_unlock(&indio_dev->info_exist_lock);
-	device_del(&indio_dev->dev);
 }
 EXPORT_SYMBOL(iio_device_unregister);
 subsys_initcall(iio_init);