| Message ID | 1374256509-7850-3-git-send-email-sakari.ailus@iki.fi (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sakari, Thank you for the patch. On Friday 19 July 2013 20:55:07 Sakari Ailus wrote: > Do not allow streaming if a pad with MEDIA_PAD_FL_MUST_CONNECT flag is not > connected by an active link. > > This patch makes it possible to avoid drivers having to check for the most > common case of link state validation: a sink pad that must be connected. > > Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> > --- > drivers/media/media-entity.c | 34 +++++++++++++++++++++++++++------- > 1 file changed, 27 insertions(+), 7 deletions(-) > > diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c > index cb30ffb..4e58f8a 100644 > --- a/drivers/media/media-entity.c > +++ b/drivers/media/media-entity.c > @@ -20,6 +20,7 @@ > * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 > USA */ > > +#include <linux/bitmap.h> > #include <linux/module.h> > #include <linux/slab.h> > #include <media/media-entity.h> > @@ -227,6 +228,7 @@ __must_check int media_entity_pipeline_start(struct > media_entity *entity, media_entity_graph_walk_start(&graph, entity); > > while ((entity = media_entity_graph_walk_next(&graph))) { > + DECLARE_BITMAP(active, entity->num_pads); > unsigned int i; > > entity->stream_count++; > @@ -240,21 +242,39 @@ __must_check int media_entity_pipeline_start(struct > media_entity *entity, if (!entity->ops || !entity->ops->link_validate) > continue; > > + bitmap_zero(active, entity->num_pads); > + > for (i = 0; i < entity->num_links; i++) { > struct media_link *link = &entity->links[i]; > - > - /* Is this pad part of an enabled link? */ > - if (!(link->flags & MEDIA_LNK_FL_ENABLED)) > - continue; > - > - /* Are we the sink or not? */ > - if (link->sink->entity != entity) > + struct media_pad *pad = link->sink->entity == entity > + ? link->sink : link->source; > + > + /* > + * Pads that either do not need to connect or > + * are connected through an enabled link are > + * fine. > + */ > + if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) > + || link->flags & MEDIA_LNK_FL_ENABLED) > + bitmap_set(active, pad->index, 1); > + > + /* > + * Link validation will only take place for > + * sink ends of the link that are enabled. > + */ > + if (link->sink != pad > + || !(link->flags & MEDIA_LNK_FL_ENABLED)) > continue; > > ret = entity->ops->link_validate(link); > if (ret < 0 && ret != -ENOIOCTLCMD) > goto error; > } > + > + if (!bitmap_full(active, entity->num_pads)) { > + ret = -EPIPE; > + goto error; > + } I'm afraid that won't work if one of the pads has no links. In that case the bitmap won't be full. I think you will have to iterate separately on the links to validate them, and on the pads to check the flags. > } > > mutex_unlock(&mdev->graph_mutex);
Hi Laurent, On Fri, Aug 09, 2013 at 01:34:46AM +0200, Laurent Pinchart wrote: > Hi Sakari, > > Thank you for the patch. > > On Friday 19 July 2013 20:55:07 Sakari Ailus wrote: > > Do not allow streaming if a pad with MEDIA_PAD_FL_MUST_CONNECT flag is not > > connected by an active link. > > > > This patch makes it possible to avoid drivers having to check for the most > > common case of link state validation: a sink pad that must be connected. > > > > Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> > > --- > > drivers/media/media-entity.c | 34 +++++++++++++++++++++++++++------- > > 1 file changed, 27 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c > > index cb30ffb..4e58f8a 100644 > > --- a/drivers/media/media-entity.c > > +++ b/drivers/media/media-entity.c > > @@ -20,6 +20,7 @@ > > * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 > > USA */ > > > > +#include <linux/bitmap.h> > > #include <linux/module.h> > > #include <linux/slab.h> > > #include <media/media-entity.h> > > @@ -227,6 +228,7 @@ __must_check int media_entity_pipeline_start(struct > > media_entity *entity, media_entity_graph_walk_start(&graph, entity); > > > > while ((entity = media_entity_graph_walk_next(&graph))) { > > + DECLARE_BITMAP(active, entity->num_pads); > > unsigned int i; > > > > entity->stream_count++; > > @@ -240,21 +242,39 @@ __must_check int media_entity_pipeline_start(struct > > media_entity *entity, if (!entity->ops || !entity->ops->link_validate) > > continue; > > > > + bitmap_zero(active, entity->num_pads); > > + > > for (i = 0; i < entity->num_links; i++) { > > struct media_link *link = &entity->links[i]; > > - > > - /* Is this pad part of an enabled link? */ > > - if (!(link->flags & MEDIA_LNK_FL_ENABLED)) > > - continue; > > - > > - /* Are we the sink or not? */ > > - if (link->sink->entity != entity) > > + struct media_pad *pad = link->sink->entity == entity > > + ? link->sink : link->source; > > + > > + /* > > + * Pads that either do not need to connect or > > + * are connected through an enabled link are > > + * fine. > > + */ > > + if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) > > + || link->flags & MEDIA_LNK_FL_ENABLED) > > + bitmap_set(active, pad->index, 1); > > + > > + /* > > + * Link validation will only take place for > > + * sink ends of the link that are enabled. > > + */ > > + if (link->sink != pad > > + || !(link->flags & MEDIA_LNK_FL_ENABLED)) > > continue; > > > > ret = entity->ops->link_validate(link); > > if (ret < 0 && ret != -ENOIOCTLCMD) > > goto error; > > } > > + > > + if (!bitmap_full(active, entity->num_pads)) { > > + ret = -EPIPE; > > + goto error; > > + } > > I'm afraid that won't work if one of the pads has no links. In that case the > bitmap won't be full. I think you will have to iterate separately on the links > to validate them, and on the pads to check the flags. Good point. I could as well add another bitmap or perhaps rather keep the information in struct media_pad, separately from flags since this is something the user can find through other means --- that way we don't add practically any runtime overhead. What do you think?
Hi Sakari, On Saturday 10 August 2013 15:16:29 Sakari Ailus wrote: > On Fri, Aug 09, 2013 at 01:34:46AM +0200, Laurent Pinchart wrote: > > On Friday 19 July 2013 20:55:07 Sakari Ailus wrote: > > > Do not allow streaming if a pad with MEDIA_PAD_FL_MUST_CONNECT flag is > > > not connected by an active link. > > > > > > This patch makes it possible to avoid drivers having to check for the > > > most common case of link state validation: a sink pad that must be > > > connected. > > > > > > Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> > > > --- > > > > > > drivers/media/media-entity.c | 34 +++++++++++++++++++++++++++------- > > > 1 file changed, 27 insertions(+), 7 deletions(-) > > > > > > diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c > > > index cb30ffb..4e58f8a 100644 > > > --- a/drivers/media/media-entity.c > > > +++ b/drivers/media/media-entity.c > > > @@ -20,6 +20,7 @@ > > > * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 > > > USA */ > > > > > > +#include <linux/bitmap.h> > > > #include <linux/module.h> > > > #include <linux/slab.h> > > > #include <media/media-entity.h> > > > @@ -227,6 +228,7 @@ __must_check int media_entity_pipeline_start(struct > > > media_entity *entity, > > > media_entity_graph_walk_start(&graph, entity); > > > > > > while ((entity = media_entity_graph_walk_next(&graph))) { > > > + DECLARE_BITMAP(active, entity->num_pads); > > > unsigned int i; > > > > > > entity->stream_count++; > > > > > > @@ -240,21 +242,39 @@ __must_check int > > > media_entity_pipeline_start(struct media_entity *entity, > > > if (!entity->ops || !entity->ops->link_validate) > > > continue; > > > > > > + bitmap_zero(active, entity->num_pads); > > > + > > > for (i = 0; i < entity->num_links; i++) { > > > struct media_link *link = &entity->links[i]; > > > - > > > - /* Is this pad part of an enabled link? */ > > > - if (!(link->flags & MEDIA_LNK_FL_ENABLED)) > > > - continue; > > > - > > > - /* Are we the sink or not? */ > > > - if (link->sink->entity != entity) > > > + struct media_pad *pad = link->sink->entity == entity > > > + ? link->sink : link->source; > > > + > > > + /* > > > + * Pads that either do not need to connect or > > > + * are connected through an enabled link are > > > + * fine. > > > + */ > > > + if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) > > > + || link->flags & MEDIA_LNK_FL_ENABLED) > > > + bitmap_set(active, pad->index, 1); > > > + > > > + /* > > > + * Link validation will only take place for > > > + * sink ends of the link that are enabled. > > > + */ > > > + if (link->sink != pad > > > + || !(link->flags & MEDIA_LNK_FL_ENABLED)) > > > continue; > > > > > > ret = entity->ops->link_validate(link); > > > if (ret < 0 && ret != -ENOIOCTLCMD) > > > goto error; > > > } > > > + > > > + if (!bitmap_full(active, entity->num_pads)) { > > > + ret = -EPIPE; > > > + goto error; > > > + } > > > > I'm afraid that won't work if one of the pads has no links. In that case > > the bitmap won't be full. I think you will have to iterate separately on > > the links to validate them, and on the pads to check the flags. > > Good point. > > I could as well add another bitmap or perhaps rather keep the information in > struct media_pad, separately from flags since this is something the user can > find through other means --- that way we don't add practically any runtime > overhead. > > What do you think? Given the number of pads we expect on an entity, is it really worth the micro- optimization ? I think I would just loop over the links and pads separately, especially given that you need to validate pads even if the entity has no link_validate operation, which is checked before the for loop over the links.
Hi Laurent, On Wed, Aug 21, 2013 at 05:22:45AM +0200, Laurent Pinchart wrote: > Hi Sakari, > > On Saturday 10 August 2013 15:16:29 Sakari Ailus wrote: > > On Fri, Aug 09, 2013 at 01:34:46AM +0200, Laurent Pinchart wrote: > > > On Friday 19 July 2013 20:55:07 Sakari Ailus wrote: > > > > Do not allow streaming if a pad with MEDIA_PAD_FL_MUST_CONNECT flag is > > > > not connected by an active link. > > > > > > > > This patch makes it possible to avoid drivers having to check for the > > > > most common case of link state validation: a sink pad that must be > > > > connected. > > > > > > > > Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> > > > > --- > > > > > > > > drivers/media/media-entity.c | 34 +++++++++++++++++++++++++++------- > > > > 1 file changed, 27 insertions(+), 7 deletions(-) > > > > > > > > diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c > > > > index cb30ffb..4e58f8a 100644 > > > > --- a/drivers/media/media-entity.c > > > > +++ b/drivers/media/media-entity.c > > > > @@ -20,6 +20,7 @@ > > > > * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 > > > > USA */ > > > > > > > > +#include <linux/bitmap.h> > > > > #include <linux/module.h> > > > > #include <linux/slab.h> > > > > #include <media/media-entity.h> > > > > @@ -227,6 +228,7 @@ __must_check int media_entity_pipeline_start(struct > > > > media_entity *entity, > > > > media_entity_graph_walk_start(&graph, entity); > > > > > > > > while ((entity = media_entity_graph_walk_next(&graph))) { > > > > + DECLARE_BITMAP(active, entity->num_pads); > > > > unsigned int i; > > > > > > > > entity->stream_count++; > > > > > > > > @@ -240,21 +242,39 @@ __must_check int > > > > media_entity_pipeline_start(struct media_entity *entity, > > > > if (!entity->ops || !entity->ops->link_validate) > > > > continue; > > > > > > > > + bitmap_zero(active, entity->num_pads); > > > > + > > > > for (i = 0; i < entity->num_links; i++) { > > > > struct media_link *link = &entity->links[i]; > > > > - > > > > - /* Is this pad part of an enabled link? */ > > > > - if (!(link->flags & MEDIA_LNK_FL_ENABLED)) > > > > - continue; > > > > - > > > > - /* Are we the sink or not? */ > > > > - if (link->sink->entity != entity) > > > > + struct media_pad *pad = link->sink->entity == entity > > > > + ? link->sink : link->source; > > > > + > > > > + /* > > > > + * Pads that either do not need to connect or > > > > + * are connected through an enabled link are > > > > + * fine. > > > > + */ > > > > + if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) > > > > + || link->flags & MEDIA_LNK_FL_ENABLED) > > > > + bitmap_set(active, pad->index, 1); > > > > + > > > > + /* > > > > + * Link validation will only take place for > > > > + * sink ends of the link that are enabled. > > > > + */ > > > > + if (link->sink != pad > > > > + || !(link->flags & MEDIA_LNK_FL_ENABLED)) > > > > continue; > > > > > > > > ret = entity->ops->link_validate(link); > > > > if (ret < 0 && ret != -ENOIOCTLCMD) > > > > goto error; > > > > } > > > > + > > > > + if (!bitmap_full(active, entity->num_pads)) { > > > > + ret = -EPIPE; > > > > + goto error; > > > > + } > > > > > > I'm afraid that won't work if one of the pads has no links. In that case > > > the bitmap won't be full. I think you will have to iterate separately on > > > the links to validate them, and on the pads to check the flags. > > > > Good point. > > > > I could as well add another bitmap or perhaps rather keep the information in > > struct media_pad, separately from flags since this is something the user can > > find through other means --- that way we don't add practically any runtime > > overhead. > > > > What do you think? > > Given the number of pads we expect on an entity, is it really worth the micro- > optimization ? I think I would just loop over the links and pads separately, > especially given that you need to validate pads even if the entity has no > link_validate operation, which is checked before the for loop over the links. I'm fine with that. Even if the information was kept in struct media_pad, a loop would be needed to dig it out. Alternatively a bitmap could be put to struct media_entity but that'd be less pretty. I'll just add another bitmap here. It can later be moved to struct media_entity if needed.
diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c index cb30ffb..4e58f8a 100644 --- a/drivers/media/media-entity.c +++ b/drivers/media/media-entity.c @@ -20,6 +20,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include <linux/bitmap.h> #include <linux/module.h> #include <linux/slab.h> #include <media/media-entity.h> @@ -227,6 +228,7 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity, media_entity_graph_walk_start(&graph, entity); while ((entity = media_entity_graph_walk_next(&graph))) { + DECLARE_BITMAP(active, entity->num_pads); unsigned int i; entity->stream_count++; @@ -240,21 +242,39 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity, if (!entity->ops || !entity->ops->link_validate) continue; + bitmap_zero(active, entity->num_pads); + for (i = 0; i < entity->num_links; i++) { struct media_link *link = &entity->links[i]; - - /* Is this pad part of an enabled link? */ - if (!(link->flags & MEDIA_LNK_FL_ENABLED)) - continue; - - /* Are we the sink or not? */ - if (link->sink->entity != entity) + struct media_pad *pad = link->sink->entity == entity + ? link->sink : link->source; + + /* + * Pads that either do not need to connect or + * are connected through an enabled link are + * fine. + */ + if (!(pad->flags & MEDIA_PAD_FL_MUST_CONNECT) + || link->flags & MEDIA_LNK_FL_ENABLED) + bitmap_set(active, pad->index, 1); + + /* + * Link validation will only take place for + * sink ends of the link that are enabled. + */ + if (link->sink != pad + || !(link->flags & MEDIA_LNK_FL_ENABLED)) continue; ret = entity->ops->link_validate(link); if (ret < 0 && ret != -ENOIOCTLCMD) goto error; } + + if (!bitmap_full(active, entity->num_pads)) { + ret = -EPIPE; + goto error; + } } mutex_unlock(&mdev->graph_mutex);
Do not allow streaming if a pad with MEDIA_PAD_FL_MUST_CONNECT flag is not connected by an active link. This patch makes it possible to avoid drivers having to check for the most common case of link state validation: a sink pad that must be connected. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> --- drivers/media/media-entity.c | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-)