On Thu Jun 19 23:47:08 2025 +0300, Laurent Pinchart wrote:
> Drivers that implement routing need to report a frame descriptor
> accordingly, with up to one entry per route. The number of frame
> descriptor entries is fixed to V4L2_FRAME_DESC_ENTRY_MAX, currently
> equal to 8. Multiple drivers therefore limit the number of routes to
> V4L2_FRAME_DESC_ENTRY_MAX, with a note indicating that the limit should
> be lifted when frame descriptor entries will be allocated dynamically.
>
> Duplicating the check in multiple drivers isn't ideal. Move it to the
> VIDIOC_SUBDEV_S_ROUTING handling code in the v4l2-subdev core.
>
> Signed-off-by: Laurent Pinchart <[email protected]>
> Reviewed-by: Jacopo Mondi <[email protected]>
> Reviewed-by: Tomi Valkeinen <[email protected]>
> Reviewed-by: Lad Prabhakar <[email protected]>
> Signed-off-by: Sakari Ailus <[email protected]>
> Signed-off-by: Hans Verkuil <[email protected]>
Patch committed.
Thanks,
Hans Verkuil
drivers/media/v4l2-core/v4l2-subdev.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
---
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c
b/drivers/media/v4l2-core/v4l2-subdev.c
index a3074f469b15..c69d1aff701f 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -1004,6 +1004,7 @@ static long subdev_do_ioctl(struct file *file, unsigned
int cmd, void *arg,
struct v4l2_subdev_route *routes =
(struct v4l2_subdev_route *)(uintptr_t)routing->routes;
struct v4l2_subdev_krouting krouting = {};
+ unsigned int num_active_routes = 0;
unsigned int i;
if (!v4l2_subdev_enable_streams_api)
@@ -1041,8 +1042,21 @@ static long subdev_do_ioctl(struct file *file, unsigned
int cmd, void *arg,
if (!(pads[route->source_pad].flags &
MEDIA_PAD_FL_SOURCE))
return -EINVAL;
+
+ if (route->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE)
+ num_active_routes++;
}
+ /*
+ * Drivers that implement routing need to report a frame
+ * descriptor accordingly, with up to one entry per route. Until
+ * the frame descriptors entries get allocated dynamically,
+ * limit the number of active routes to
+ * V4L2_FRAME_DESC_ENTRY_MAX.
+ */
+ if (num_active_routes > V4L2_FRAME_DESC_ENTRY_MAX)
+ return -E2BIG;
+
/*
* If the driver doesn't support setting routing, just return
* the routing table.
