Hi Hans,
On Tue, Aug 08, 2023 at 10:15:45AM +0200, Hans Verkuil wrote:
> On 08/08/2023 09:55, Sakari Ailus wrote:
> > Internal source pads will be used as routing endpoints in V4L2
> > [GS]_ROUTING IOCTLs, to indicate that the stream begins in the entity.
> >
> > Also prevent creating links to pads that have been flagged as internal.
> >
> > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > ---
> > Documentation/userspace-api/media/glossary.rst | 6 ++++++
> > Documentation/userspace-api/media/mediactl/media-types.rst | 6 ++++++
> > drivers/media/mc/mc-entity.c | 6 +++++-
> > include/uapi/linux/media.h | 1 +
> > 4 files changed, 18 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/userspace-api/media/glossary.rst b/Documentation/userspace-api/media/glossary.rst
> > index 96a360edbf3b..f7b99a4527c7 100644
> > --- a/Documentation/userspace-api/media/glossary.rst
> > +++ b/Documentation/userspace-api/media/glossary.rst
> > @@ -173,6 +173,12 @@ Glossary
> > An integrated circuit that integrates all components of a computer
> > or other electronic systems.
> >
> > +_media-glossary-stream:
> > + Stream
> > + A distinct flow of data (image data or metadata) over a media pipeline
> > + from source to sink. A source may be e.g. an image sensor and a sink
> > + e.g. a memory buffer.
> > +
> > V4L2 API
> > **V4L2 userspace API**
> >
> > diff --git a/Documentation/userspace-api/media/mediactl/media-types.rst b/Documentation/userspace-api/media/mediactl/media-types.rst
> > index 0ffeece1e0c8..28941da27790 100644
> > --- a/Documentation/userspace-api/media/mediactl/media-types.rst
> > +++ b/Documentation/userspace-api/media/mediactl/media-types.rst
> > @@ -361,6 +361,7 @@ Types and flags used to represent the media graph elements
> > .. _MEDIA-PAD-FL-SINK:
> > .. _MEDIA-PAD-FL-SOURCE:
> > .. _MEDIA-PAD-FL-MUST-CONNECT:
> > +.. _MEDIA-PAD-FL-INTERNAL:
> >
> > .. flat-table:: Media pad flags
> > :header-rows: 0
> > @@ -382,6 +383,11 @@ Types and flags used to represent the media graph elements
> > when this flag isn't set; the absence of the flag doesn't imply
> > there is none.
> >
> > + * - ``MEDIA_PAD_FL_INTERNAL``
> > + - The internal flag indicates an internal pad that has no external
> > + connections. Such a pad shall not be connected with a link. The
> > + internal flag indicates that the :ref:``stream
> > + <media-glossary-stream>`` either starts or ends in the entity.
> >
> > One and only one of ``MEDIA_PAD_FL_SINK`` and ``MEDIA_PAD_FL_SOURCE``
> > must be set for every pad.
> > diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
> > index 4991281dcccc..03a9e0b8ebab 100644
> > --- a/drivers/media/mc/mc-entity.c
> > +++ b/drivers/media/mc/mc-entity.c
> > @@ -1071,7 +1071,8 @@ int media_get_pad_index(struct media_entity *entity, u32 pad_type,
> >
> > for (i = 0; i < entity->num_pads; i++) {
> > if ((entity->pads[i].flags &
> > - (MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_SOURCE)) != pad_type)
> > + (MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_SOURCE |
> > + MEDIA_PAD_FL_INTERNAL)) != pad_type)
> > continue;
> >
> > if (entity->pads[i].sig_type == sig_type)
> > @@ -1094,6 +1095,9 @@ media_create_pad_link(struct media_entity *source, u16 source_pad,
> > return -EINVAL;
> > if (WARN_ON(!(source->pads[source_pad].flags & MEDIA_PAD_FL_SOURCE)))
> > return -EINVAL;
> > + if (WARN_ON(source->pads[source_pad].flags & MEDIA_PAD_FL_SOURCE &&
> > + source->pads[source_pad].flags & MEDIA_PAD_FL_INTERNAL))
>
> Even though this code is correct, I prefer to have () around the 'x & y' parts.
> It avoids confusion for the reader.
There actually should be a check here that neither of the pads have
internal flag set --- internal pads may not be connected by a link. I'll
fix that for v4. This was actually a leftover from the "internal source"
flag.
>
> Up to you, though.
I'd prefer to keep it as-is. :-)
--
Regards,
Sakari Ailus
