iio: buffer: document that buffer callback must be context safe

Document that the callback registered with iio_channel_get_all_cb()
must be safe to call from any context since it is called from by
iio_push_to_buffer() which can be called in any context.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/buffer/industrialio-buffer-cb.c b/drivers/iio/buffer/industrialio-buffer-cb.c
index 3e27385069edb5b717a4c56e72dff2c0a238fa07..f4ebff9684936365ec179489d9041d8bdbe58738 100644 (file)
--- a/drivers/iio/buffer/industrialio-buffer-cb.c
+++ b/drivers/iio/buffer/industrialio-buffer-cb.c
@@ -13,6 +13,7 @@
 
 struct iio_cb_buffer {
        struct iio_buffer buffer;
+       /* Must be safe to call from any context (e.g. must not sleep). */
        int (*cb)(const void *data, void *private);
        void *private;
        struct iio_channel *channels;

diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index a38b277c2c02cb85a766d645a046bdfa534db51a..5039558267e4c17b2e09246036d0df352e242d06 100644 (file)
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -131,7 +131,8 @@ struct iio_cb_buffer;
 /**
  * iio_channel_get_all_cb() - register callback for triggered capture
  * @dev:               Pointer to client device.
- * @cb:                        Callback function.
+ * @cb:                        Callback function. Must be safe to call from any context
+ *                     (e.g. must not sleep).
  * @private:           Private data passed to callback.
  *
  * NB right now we have no ability to mux data from multiple devices.