[v2,1/1] pipeline: rpi: Fix for enumerating the media graphs
diff mbox series

Message ID 20250627094809.1296587-2-naush@raspberrypi.com
State New
Headers show
Series
  • Raspberry Pi: Media graph enumeration updates
Related show

Commit Message

Naushir Patuck June 27, 2025, 9:46 a.m. UTC 
When there are multiple entities between the sensor and CFE device (e.g.
a serialiser and deserialiser or multiple mux devices), the media graph
enumeration would work incorrectly and report that the frontend entity
was not found. This is because the found flag was stored locally in a
boolean and got lost in the recursion.

Fix this by explicitly tracking and returning the frontend found flag
through the return value of enumerateVideoDevices(). This ensures the
flag does not get lost through nested recursion.

This flag can also be used to fail a camera registration if the frontend
is not found.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Umang Jain <uajain@igalia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../pipeline/rpi/common/pipeline_base.cpp     | 22 +++++++++++--------
 .../pipeline/rpi/common/pipeline_base.h       |  2 +-
 2 files changed, 14 insertions(+), 10 deletions(-)

Patch
diff mbox series 

diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
index e14d3b913aaa..eafe94427dbc 100644
--- a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
+++ b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
@@ -806,7 +806,8 @@  int PipelineHandlerBase::registerCamera(std::unique_ptr<RPi::CameraData> &camera
 	 * chain. There may be a cascade of devices in this chain!
 	 */
 	MediaLink *link = sensorEntity->getPadByIndex(0)->links()[0];
-	data->enumerateVideoDevices(link, frontendName);
+	if (!data->enumerateVideoDevices(link, frontendName))
+		return -EINVAL;
 
 	ipa::RPi::InitResult result;
 	if (data->loadIPA(&result)) {
@@ -1018,16 +1019,20 @@  void CameraData::freeBuffers()
  *          | Sensor2 |   | Sensor3 |
  *          +---------+   +---------+
  */
-void CameraData::enumerateVideoDevices(MediaLink *link, const std::string &frontend)
+bool CameraData::enumerateVideoDevices(MediaLink *link, const std::string &frontend)
 {
 	const MediaPad *sinkPad = link->sink();
 	const MediaEntity *entity = sinkPad->entity();
 	bool frontendFound = false;
 
+	/* Once we reach the Frontend entity, we are done. */
+	if (link->sink()->entity()->name() == frontend)
+		return true;
+
 	/* We only deal with Video Mux and Bridge devices in cascade. */
 	if (entity->function() != MEDIA_ENT_F_VID_MUX &&
 	    entity->function() != MEDIA_ENT_F_VID_IF_BRIDGE)
-		return;
+		return false;
 
 	/* Find the source pad for this Video Mux or Bridge device. */
 	const MediaPad *sourcePad = nullptr;
@@ -1039,7 +1044,7 @@  void CameraData::enumerateVideoDevices(MediaLink *link, const std::string &front
 			 * and this branch in the cascade.
 			 */
 			if (sourcePad)
-				return;
+				return false;
 
 			sourcePad = pad;
 		}
@@ -1056,12 +1061,9 @@  void CameraData::enumerateVideoDevices(MediaLink *link, const std::string &front
 	 * other Video Mux and Bridge devices.
 	 */
 	for (MediaLink *l : sourcePad->links()) {
-		enumerateVideoDevices(l, frontend);
-		/* Once we reach the Frontend entity, we are done. */
-		if (l->sink()->entity()->name() == frontend) {
-			frontendFound = true;
+		frontendFound = enumerateVideoDevices(l, frontend);
+		if (frontendFound)
 			break;
-		}
 	}
 
 	/* This identifies the end of our entity enumeration recursion. */
@@ -1076,6 +1078,8 @@  void CameraData::enumerateVideoDevices(MediaLink *link, const std::string &front
 			bridgeDevices_.clear();
 		}
 	}
+
+	return frontendFound;
 }
 
 int CameraData::loadPipelineConfiguration()
diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.h b/src/libcamera/pipeline/rpi/common/pipeline_base.h
index 4c5743e04f86..4bce4ec4f978 100644
--- a/src/libcamera/pipeline/rpi/common/pipeline_base.h
+++ b/src/libcamera/pipeline/rpi/common/pipeline_base.h
@@ -68,7 +68,7 @@  public:
 	void freeBuffers();
 	virtual void platformFreeBuffers() = 0;
 
-	void enumerateVideoDevices(MediaLink *link, const std::string &frontend);
+	bool enumerateVideoDevices(MediaLink *link, const std::string &frontend);
 
 	int loadPipelineConfiguration();
 	int loadIPA(ipa::RPi::InitResult *result);