Move validation of the links between video devices and subdevs,
performed manually in vsp1_video_streamon(), to the video device
.link_validate() handler.
This is how drivers should be implemented, but sadly, doing so for the
vsp1 driver could break userspace, introducing a regression. This patch
serves as an example to showcase usage of the .link_validate()
operation, but should not be merged.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
---
.../media/platform/renesas/vsp1/vsp1_video.c | 98 +++++++------------
1 file changed, 37 insertions(+), 61 deletions(-)
diff --git a/drivers/media/platform/renesas/vsp1/vsp1_video.c b/drivers/media/platform/renesas/vsp1/vsp1_video.c
index e728f9f5160e..14575698bbe7 100644
--- a/drivers/media/platform/renesas/vsp1/vsp1_video.c
+++ b/drivers/media/platform/renesas/vsp1/vsp1_video.c
@@ -45,51 +45,6 @@
* Helper functions
*/
-static struct v4l2_subdev *
-vsp1_video_remote_subdev(struct media_pad *local, u32 *pad)
-{
- struct media_pad *remote;
-
- remote = media_pad_remote_pad_first(local);
- if (!remote || !is_media_entity_v4l2_subdev(remote->entity))
- return NULL;
-
- if (pad)
- *pad = remote->index;
-
- return media_entity_to_v4l2_subdev(remote->entity);
-}
-
-static int vsp1_video_verify_format(struct vsp1_video *video)
-{
- struct v4l2_subdev_format fmt = {
- .which = V4L2_SUBDEV_FORMAT_ACTIVE,
- };
- struct v4l2_subdev *subdev;
- int ret;
-
- subdev = vsp1_video_remote_subdev(&video->pad, &fmt.pad);
- if (subdev == NULL)
- return -EINVAL;
-
- ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
- if (ret < 0)
- return ret == -ENOIOCTLCMD ? -EINVAL : ret;
-
- if (video->rwpf->fmtinfo->mbus != fmt.format.code ||
- video->rwpf->format.height != fmt.format.height ||
- video->rwpf->format.width != fmt.format.width) {
- dev_dbg(video->vsp1->dev,
- "Format mismatch: 0x%04x/%ux%u != 0x%04x/%ux%u\n",
- video->rwpf->fmtinfo->mbus, video->rwpf->format.width,
- video->rwpf->format.height, fmt.format.code,
- fmt.format.width, fmt.format.height);
- return -EPIPE;
- }
-
- return 0;
-}
-
static int __vsp1_video_try_format(struct vsp1_video *video,
struct v4l2_pix_format_mplane *pix,
const struct vsp1_format_info **fmtinfo)
@@ -991,14 +946,6 @@ vsp1_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
mutex_unlock(&mdev->graph_mutex);
- /*
- * Verify that the configured format matches the output of the connected
- * subdev.
- */
- ret = vsp1_video_verify_format(video);
- if (ret < 0)
- goto err_stop;
-
/* Start the queue. */
ret = vb2_streamon(&video->queue, type);
if (ret < 0)
@@ -1087,14 +1034,43 @@ static const struct v4l2_file_operations vsp1_video_fops = {
static int vsp1_video_link_validate(struct media_link *link)
{
- /*
- * Ideally, link validation should be implemented here instead of
- * calling vsp1_video_verify_format() in vsp1_video_streamon()
- * manually. That would however break userspace that start one video
- * device before configures formats on other video devices in the
- * pipeline. This operation is just a no-op to silence the warnings
- * from v4l2_subdev_link_validate().
- */
+ struct v4l2_subdev_format fmt = {
+ .which = V4L2_SUBDEV_FORMAT_ACTIVE,
+ };
+ struct v4l2_subdev *subdev;
+ struct media_entity *entity;
+ struct media_pad *remote;
+ struct vsp1_video *video;
+ int ret;
+
+ if (is_media_entity_v4l2_video_device(link->source->entity)) {
+ entity = link->source->entity;
+ remote = link->sink;
+ } else {
+ entity = link->sink->entity;
+ remote = link->source;
+ }
+
+ fmt.pad = remote->index;
+
+ subdev = media_entity_to_v4l2_subdev(remote->entity);
+ ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
+ if (ret < 0)
+ return ret == -ENOIOCTLCMD ? -EINVAL : ret;
+
+ video = to_vsp1_video(media_entity_to_video_device(entity));
+
+ if (video->rwpf->fmtinfo->mbus != fmt.format.code ||
+ video->rwpf->format.height != fmt.format.height ||
+ video->rwpf->format.width != fmt.format.width) {
+ dev_dbg(video->vsp1->dev,
+ "Format mismatch: 0x%04x/%ux%u != 0x%04x/%ux%u\n",
+ video->rwpf->fmtinfo->mbus, video->rwpf->format.width,
+ video->rwpf->format.height, fmt.format.code,
+ fmt.format.width, fmt.format.height);
+ return -EPIPE;
+ }
+
return 0;
}
--
Regards,
Laurent Pinchart
