[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>

1 files changed, 25 insertions, 16 deletions

diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index ff5a20afa69..df3a0ec7fd2 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;
 }
 
 /* -----------------------------------------------------------------------------