staging:iio: Drop {mark,unmark}_in_use callbacks

These callbacks are currently used by the individual buffer implementations to
ensure that the request_update callback is not issued while the buffer is in use.
But the core already provides sufficient measures to prevent this from happening
in the first place. So it is safe to remove them.

There is one functional change due to this patch. Since the buffer is no longer
marked as in use when the chrdev is opened, it is now possible to enable the
buffer while it is opened. This did not work before, because mark_param_change
did fail if the buffer was marked as in use.

Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 0 insertions, 4 deletions

diff --git a/drivers/staging/iio/Documentation/ring.txt b/drivers/staging/iio/Documentation/ring.txt
index 0f21479ef4ef..e33807761cd7 100644
--- a/drivers/staging/iio/Documentation/ring.txt
+++ b/drivers/staging/iio/Documentation/ring.txt
@@ -23,10 +23,6 @@ The function pointers within here are used to allow the core to handle
 as much buffer functionality as possible. Note almost all of these
 are optional.
 
-mark_in_use, unmark_in_use
-  Basically indicate that not changes should be made to the buffer state that
-  will effect the form of the data being captures (e.g. scan elements or length)
-
 store_to
   If possible, push data to the buffer.