On 03/10/2023 15:08, Sakari Ailus wrote:
On VIDIOC_SUBDEV_[GS]_ROUTING, only return as many routes back to the user
as there's room. Do not consider it an error if more routes existed.
Simply inform the user there are more routes.
Inform how? And I agree with Hans here. How about return ENOSPC, but the
kernel fills in num_routes to tell the userspace how many there actually
are?
Tomi
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
.../userspace-api/media/v4l/vidioc-subdev-g-routing.rst | 4 ----
drivers/media/v4l2-core/v4l2-subdev.c | 8 ++------
2 files changed, 2 insertions(+), 10 deletions(-)
diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
index ced53ea5f23c..99d3c15fd759 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
@@ -145,10 +145,6 @@ On success 0 is returned, on error -1 and the ``errno`` variable is set
appropriately. The generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.
-ENOSPC
- The application provided ``num_routes`` is not big enough to contain
- all the available routes the subdevice exposes.
-
EINVAL
The sink or source pad identifiers reference a non-existing pad, or reference
pads of different types (ie. the sink_pad identifiers refers to a source pad).
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 9a34e13dfd96..dd48e7e549fb 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -956,14 +956,10 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
krouting = &state->routing;
- if (routing->len_routes < krouting->num_routes) {
- routing->num_routes = krouting->num_routes;
- return -ENOSPC;
- }
-
memcpy((struct v4l2_subdev_route *)(uintptr_t)routing->routes,
krouting->routes,
- krouting->num_routes * sizeof(*krouting->routes));
+ min(krouting->num_routes, routing->len_routes) *
+ sizeof(*krouting->routes));
routing->num_routes = krouting->num_routes;
return 0;
