[PATCH v16.1] media: subdev: Require code change to enable [GS]_ROUTING

[Tomi Valkeinen]

Streams API is an experimental feature. To use Streams API, the user
needs to change a variable in v4l2-subdev.c and recompile the kernel.

This commit should be reverted when the Streams API is deemed ready for
production use.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
---

Here's a minor update to the patch:
- Fix unused var warning
- Don't initialize the static var to 0

 drivers/media/v4l2-core/v4l2-subdev.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 61b429016a2f..a576b22164b0 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -23,6 +23,15 @@
 #include <media/v4l2-fh.h>
 #include <media/v4l2-ioctl.h>
 
+#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
+/*
+ * Streams API is an experimental feature. To use Streams API, set
+ * 'v4l2_subdev_enable_streams_api' to 1 below.
+ */
+
+static bool v4l2_subdev_enable_streams_api;
+#endif
+
 /*
  * Maximum stream ID is 63 for now, as we use u64 bitmask to represent a set
  * of streams.
@@ -751,6 +760,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 		struct v4l2_subdev_routing *routing = arg;
 		struct v4l2_subdev_krouting *krouting;
 
+		if (!v4l2_subdev_enable_streams_api)
+			return -ENOIOCTLCMD;
+
 		if (!(sd->flags & V4L2_SUBDEV_FL_STREAMS))
 			return -ENOIOCTLCMD;
 
@@ -778,6 +790,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 		struct v4l2_subdev_krouting krouting = {};
 		unsigned int i;
 
+		if (!v4l2_subdev_enable_streams_api)
+			return -ENOIOCTLCMD;
+
 		if (!(sd->flags & V4L2_SUBDEV_FL_STREAMS))
 			return -ENOIOCTLCMD;
 
-- 
2.34.1