[media] media: Change media device link_notify behaviour

Currently the media device link_notify callback is invoked before the
actual change of state of a link when the link is being enabled, and
after the actual change of state when the link is being disabled.
This doesn't allow a media device driver to perform any operations
on a full graph before a link is disabled, as well as performing
any tasks on a modified graph right after a link's state is changed.
This patch modifies signature of the link_notify callback. This
callback is now called always before and after a link's state change.
To distinguish the notifications a 'notification' argument is added
to the link_notify callback: MEDIA_DEV_NOTIFY_PRE_LINK_CH indicates
notification before link's state change and
MEDIA_DEV_NOTIFY_POST_LINK_CH corresponds to a notification after
link flags change.

[mchehab@redhat.com: whitespace cleanups]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 40 insertions, 37 deletions

diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
index 0438209d020a..df72f7d99d80 100644
--- a/drivers/media/media-entity.c
+++ b/drivers/media/media-entity.c
@@ -496,25 +496,17 @@ int __media_entity_setup_link(struct media_link *link, u32 flags)
 
         mdev = source->parent;
 
-        if ((flags & MEDIA_LNK_FL_ENABLED) && mdev->link_notify) {
-                ret = mdev->link_notify(link->source, link->sink,
-                                        MEDIA_LNK_FL_ENABLED);
+        if (mdev->link_notify) {
+                ret = mdev->link_notify(link, flags,
+                                        MEDIA_DEV_NOTIFY_PRE_LINK_CH);
                 if (ret < 0)
                         return ret;
         }
 
         ret = __media_entity_setup_link_notify(link, flags);
-        if (ret < 0)
-                goto err;
 
-        if (!(flags & MEDIA_LNK_FL_ENABLED) && mdev->link_notify)
-                mdev->link_notify(link->source, link->sink, 0);
-
-        return 0;
-
-err:
-        if ((flags & MEDIA_LNK_FL_ENABLED) && mdev->link_notify)
-                mdev->link_notify(link->source, link->sink, 0);
+        if (mdev->link_notify)
+                mdev->link_notify(link, flags, MEDIA_DEV_NOTIFY_POST_LINK_CH);
 
         return ret;
 }
diff --git a/drivers/media/platform/exynos4-is/media-dev.c b/drivers/media/platform/exynos4-is/media-dev.c
index b5624931d16d..5298dd6680ae 100644
--- a/drivers/media/platform/exynos4-is/media-dev.c
+++ b/drivers/media/platform/exynos4-is/media-dev.c
@@ -1287,34 +1287,36 @@ int fimc_md_set_camclk(struct v4l2_subdev *sd, bool on)
         return __fimc_md_set_camclk(fmd, si, on);
 }
 
-static int fimc_md_link_notify(struct media_pad *source,
-                               struct media_pad *sink, u32 flags)
+static int fimc_md_link_notify(struct media_link *link, u32 flags,
+                                                unsigned int notification)
 {
+        struct media_entity *sink = link->sink->entity;
         struct exynos_video_entity *ve;
         struct video_device *vdev;
         struct fimc_pipeline *pipeline;
         int i, ret = 0;
 
-        if (media_entity_type(sink->entity) != MEDIA_ENT_T_DEVNODE_V4L)
+        if (media_entity_type(sink) != MEDIA_ENT_T_DEVNODE_V4L ||
+            notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH)
                 return 0;
 
-        vdev = media_entity_to_video_device(sink->entity);
+        vdev = media_entity_to_video_device(sink);
         ve = vdev_to_exynos_video_entity(vdev);
         pipeline = to_fimc_pipeline(ve->pipe);
 
-        if (!(flags & MEDIA_LNK_FL_ENABLED) && pipeline->subdevs[IDX_SENSOR]) {
-                if (sink->entity->use_count > 0)
+        if (!(link->flags & MEDIA_LNK_FL_ENABLED) && pipeline->subdevs[IDX_SENSOR]) {
+                if (sink->use_count > 0)
                         ret = __fimc_pipeline_close(ve->pipe);
 
                 for (i = 0; i < IDX_MAX; i++)
                         pipeline->subdevs[i] = NULL;
-        } else if (sink->entity->use_count > 0) {
+        } else if (sink->use_count > 0) {
                 /*
                  * Link activation. Enable power of pipeline elements only if
                  * the pipeline is already in use, i.e. its video node is open.
                  * Recreate the controls destroyed during the link deactivation.
                  */
-                ret = __fimc_pipeline_open(ve->pipe, sink->entity, true);
+                ret = __fimc_pipeline_open(ve->pipe, sink, true);
         }
 
         return ret ? -EPIPE : ret;
diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index ff5a20afa691..df3a0ec7fd2c 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -792,9 +792,9 @@ int omap3isp_pipeline_pm_use(struct media_entity *entity, int use)
 
 /*
  * isp_pipeline_link_notify - Link management notification callback
- * @source: Pad at the start of the link
- * @sink: Pad at the end of the link
+ * @link: The link
  * @flags: New link flags that will be applied
+ * @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*)
  *
  * React to link management on powered pipelines by updating the use count of
  * all entities in the source and sink sides of the link. Entities are powered
@@ -804,29 +804,38 @@ int omap3isp_pipeline_pm_use(struct media_entity *entity, int use)
  * off is assumed to never fail. This function will not fail for disconnection
  * events.
  */
-static int isp_pipeline_link_notify(struct media_pad *source,
-                                    struct media_pad *sink, u32 flags)
+static int isp_pipeline_link_notify(struct media_link *link, u32 flags,
+                                    unsigned int notification)
 {
-        int source_use = isp_pipeline_pm_use_count(source->entity);
-        int sink_use = isp_pipeline_pm_use_count(sink->entity);
+        struct media_entity *source = link->source->entity;
+        struct media_entity *sink = link->sink->entity;
+        int source_use = isp_pipeline_pm_use_count(source);
+        int sink_use = isp_pipeline_pm_use_count(sink);
         int ret;
 
-        if (!(flags & MEDIA_LNK_FL_ENABLED)) {
+        if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
+            !(link->flags & MEDIA_LNK_FL_ENABLED)) {
                 /* Powering off entities is assumed to never fail. */
-                isp_pipeline_pm_power(source->entity, -sink_use);
-                isp_pipeline_pm_power(sink->entity, -source_use);
+                isp_pipeline_pm_power(source, -sink_use);
+                isp_pipeline_pm_power(sink, -source_use);
                 return 0;
         }
 
-        ret = isp_pipeline_pm_power(source->entity, sink_use);
-        if (ret < 0)
-                return ret;
+        if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
+                (flags & MEDIA_LNK_FL_ENABLED)) {
 
-        ret = isp_pipeline_pm_power(sink->entity, source_use);
-        if (ret < 0)
-                isp_pipeline_pm_power(source->entity, -sink_use);
+                ret = isp_pipeline_pm_power(source, sink_use);
+                if (ret < 0)
+                        return ret;
 
-        return ret;
+                ret = isp_pipeline_pm_power(sink, source_use);
+                if (ret < 0)
+                        isp_pipeline_pm_power(source, -sink_use);
+
+                return ret;
+        }
+
+        return 0;
 }
 
 /* -----------------------------------------------------------------------------