@@ -43,7 +43,10 @@ The configuration applies to all requested lines.
The same :ref:`gpio-get-linehandle-config-rules` and
:ref:`gpio-get-linehandle-config-support` that apply when requesting the
-lines also apply when updating the line configuration.
+lines also apply when updating the line configuration, with the additional
+restriction that a direction flag must be set. Requesting an invalid
+configuration, including without a direction flag set, is an error
+(**EINVAL**).
The motivating use case for this command is changing direction of
bi-directional lines between input and output, but it may be used more
Update description of reconfiguration rules, adding requirement that a direction flag be set or the configuration is considered invalid. Signed-off-by: Kent Gibson <warthog618@gmail.com> --- .../userspace-api/gpio/gpio-handle-set-config-ioctl.rst | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)