media: ipu-bridge: Serialise calls to IPU bridge init

The IPU bridge initialisation will be called from multiple locations in
the future. Serialise the access to devices' fwnodes in this context.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Author: Sakari Ailus

drivers/media/pci/intel/ipu-bridge.c

@@ -766,6 +766,8 @@ static int ipu_bridge_check_fwnode_graph(struct fwnode_handle *fwnode)
 	return ipu_bridge_check_fwnode_graph(fwnode->secondary);
 }
 
+static DEFINE_MUTEX(ipu_bridge_mutex);
+
 int ipu_bridge_init(struct device *dev,
 		    ipu_parse_sensor_fwnode_t parse_sensor_fwnode)
 {
@@ -774,6 +776,8 @@ int ipu_bridge_init(struct device *dev,
 	unsigned int i;
 	int ret;
 
+	guard(mutex)(&ipu_bridge_mutex);
+
 	if (!ipu_bridge_check_fwnode_graph(dev_fwnode(dev)))
 		return 0;