On 29/07/2022 12:12, Satish Nagireddy wrote:
Hi Tomi,
Thanks for the patch.
On Wed, Jul 27, 2022 at 3:37 AM Tomi Valkeinen
<tomi.valkeinen@xxxxxxxxxxxxxxxx> wrote:
Update v4l2_subdev_link_validate() to use routing and streams for
validation.
Instead of just looking at the format on the pad on both ends of the
link, the routing tables are used to collect all the streams going from
the source to the sink over the link, and the streams' formats on both
ends of the link are verified.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-subdev.c | 255 ++++++++++++++++++++++++--
1 file changed, 235 insertions(+), 20 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index d26715cbd955..7ca2337ca8d3 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -16,6 +16,7 @@
#include <linux/videodev2.h>
#include <linux/export.h>
#include <linux/version.h>
+#include <linux/sort.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
@@ -1069,7 +1070,7 @@ int v4l2_subdev_link_validate_default(struct v4l2_subdev *sd,
EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate_default);
static int
-v4l2_subdev_link_validate_get_format(struct media_pad *pad,
+v4l2_subdev_link_validate_get_format(struct media_pad *pad, u32 stream,
struct v4l2_subdev_format *fmt)
{
if (is_media_entity_v4l2_subdev(pad->entity)) {
@@ -1078,7 +1079,11 @@ v4l2_subdev_link_validate_get_format(struct media_pad *pad,
fmt->which = V4L2_SUBDEV_FORMAT_ACTIVE;
fmt->pad = pad->index;
- return v4l2_subdev_call_state_active(sd, pad, get_fmt, fmt);
+ fmt->stream = stream;
+
+ return v4l2_subdev_call(sd, pad, get_fmt,
+ v4l2_subdev_get_locked_active_state(sd),
+ fmt);
}
WARN(pad->entity->function != MEDIA_ENT_F_IO_V4L,
@@ -1088,31 +1093,241 @@ v4l2_subdev_link_validate_get_format(struct media_pad *pad,
return -EINVAL;
}
-int v4l2_subdev_link_validate(struct media_link *link)
+static int cmp_u32(const void *a, const void *b)
{
- struct v4l2_subdev *sink;
- struct v4l2_subdev_format sink_fmt, source_fmt;
- int rval;
+ u32 a32 = *(u32 *)a;
+ u32 b32 = *(u32 *)b;
- rval = v4l2_subdev_link_validate_get_format(
- link->source, &source_fmt);
- if (rval < 0)
- return 0;
+ return a32 > b32 ? 1 : (a32 < b32 ? -1 : 0);
+}
+
+static int v4l2_link_validate_get_streams(struct media_link *link,
+ bool is_source, u32 *out_num_streams,
+ const u32 **out_streams,
+ bool *allocated)
I have a suggestion to refactor this function a bit to avoid the usage
of is_source boolean, hopefully that makes this implementation look
better.
Here is my idea: Pass the media_pad (source or sink) to the function
directly and drop the parameters link and is_source. Then...
+{
+ static const u32 default_streams[] = { 0 };
+ struct v4l2_subdev_krouting *routing;
+ struct v4l2_subdev *subdev;
+ u32 num_streams;
+ u32 *streams;
+ unsigned int i;
+ struct v4l2_subdev_state *state;
+ int ret;
- rval = v4l2_subdev_link_validate_get_format(
- link->sink, &sink_fmt);
- if (rval < 0)
+ if (is_source)
+ subdev = media_entity_to_v4l2_subdev(link->source->entity);
+ else
+ subdev = media_entity_to_v4l2_subdev(link->sink->entity);
... we can avoid the if check here and directly assign subdev as below.
subdev = media_entity_to_v4l2_subdev(pad->entity);
Then...
+
+ if (!(subdev->flags & V4L2_SUBDEV_FL_STREAMS)) {
+ *out_num_streams = 1;
+ *out_streams = default_streams;
+ *allocated = false;
return 0;
+ }
- sink = media_entity_to_v4l2_subdev(link->sink->entity);
+ state = v4l2_subdev_get_locked_active_state(subdev);
- rval = v4l2_subdev_call(sink, pad, link_validate, link,
- &source_fmt, &sink_fmt);
- if (rval != -ENOIOCTLCMD)
- return rval;
+ routing = &state->routing;
+
+ streams = kmalloc_array(routing->num_routes, sizeof(u32), GFP_KERNEL);
+ if (!streams)
+ return -ENOMEM;
+
+ num_streams = 0;
+
+ for (i = 0; i < routing->num_routes; ++i) {
+ struct v4l2_subdev_route *route = &routing->routes[i];
+ int j;
+ u32 route_pad;
+ u32 route_stream;
+ u32 link_pad;
+
+ if (!(route->flags & V4L2_SUBDEV_ROUTE_FL_ACTIVE))
+ continue;
+
+ if (is_source) {
+ route_pad = route->source_pad;
+ route_stream = route->source_stream;
+ link_pad = link->source->index;
+ } else {
+ route_pad = route->sink_pad;
+ route_stream = route->sink_stream;
+ link_pad = link->sink->index;
+ }
This can be achieved by checking pad->flags against
MEDIA_PAD_FL_SOURCE or MEDIA_PAD_FL_SINK.
Please let me know your opinion.
Yes, I like this. It gets rid of that annoying 'is_source' =).
+
+ if (route_pad != link_pad)
+ continue;
+
+ /* look for duplicates */
+ for (j = 0; j < num_streams; ++j) {
+ if (streams[j] == route_stream) {
+ ret = -EINVAL;
+ goto free_streams;
+ }
+ }
This is good logic, but seems to be a bit inefficient as it is
repeatedly checking the array from the start.
I do not have a better idea :)
+
+ streams[num_streams++] = route_stream;
+ }
+
+ sort(streams, num_streams, sizeof(u32), &cmp_u32, NULL);
+
+ *out_num_streams = num_streams;
+ *out_streams = streams;
+ *allocated = true;
+
+ return 0;
+
+free_streams:
+ kfree(streams);
+
+ return ret;
+}
+
+static int v4l2_subdev_link_validate_locked(struct media_link *link)
+{
+ struct v4l2_subdev *sink_subdev =
+ media_entity_to_v4l2_subdev(link->sink->entity);
+ struct device *dev = sink_subdev->entity.graph_obj.mdev->dev;
+ u32 num_source_streams;
+ const u32 *source_streams;
+ bool source_allocated;
+ u32 num_sink_streams;
+ const u32 *sink_streams;
+ bool sink_allocated;
+ unsigned int sink_idx;
+ unsigned int source_idx;
+ int ret;
+
+ dev_dbg(dev, "validating link \"%s\":%u -> \"%s\":%u\n",
+ link->source->entity->name, link->source->index,
+ link->sink->entity->name, link->sink->index);
+
+ ret = v4l2_link_validate_get_streams(link, true, &num_source_streams,
This function call can be modified as below
v4l2_link_validate_get_streams(link->source, &num_source_streams,
+ &source_streams,
+ &source_allocated);
+ if (ret)
+ return ret;
+
+ ret = v4l2_link_validate_get_streams(link, false, &num_sink_streams,
This function call can be modified as below
v4l2_link_validate_get_streams(link->sink, &num_source_streams,
+ &sink_streams, &sink_allocated);
+ if (ret)
+ goto free_source;
+
+ /*
+ * It is ok to have more source streams than sink streams as extra
+ * source streams can just be ignored by the receiver, but having extra
+ * sink streams is an error as streams must have a source.
+ */
+ if (num_source_streams < num_sink_streams) {
+ dev_err(dev,
+ "Not enough source streams: %d < %d\n",
+ num_source_streams, num_sink_streams);
+ ret = -EINVAL;
+ goto free_sink;
+ }
+
+ /* Validate source and sink stream formats */
+
+ source_idx = 0;
Nit, This can be assigned at the declaration.
True, but I often like to initialize the variables closer to the
use if the function is a bit on the longer side.
Although nowadays we could do:
for (unsigned int sink_idx = 0, source_idx = 0; sink_idx < num_sink_streams; ++sink_idx) {
Tomi
