[PATCH v3 2/2] remoteproc: enhance rproc_put() for clusters

[Tanmay Shah]

This patch enhances rproc_put() to support remoteproc clusters
with multiple child nodes as in rproc_get_by_phandle().

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Link: https://lore.kernel.org/oe-kbuild-all/202303221441.cuBnpvye-lkp@xxxxxxxxx/
Signed-off-by: Tarak Reddy <tarak.reddy@xxxxxxx>
Signed-off-by: Tanmay Shah <tanmay.shah@xxxxxxx>
---

Changes in v3:
  - remove module_put call that was introduced in the patch by mistake
  - remove redundant check in rproc_put
  - Add inline comments in rproc_put that explains functionality

Changes in v2:
  - Introduce this patch to fix rproc_put as per modified rproc_get_by_phandle

 drivers/remoteproc/remoteproc_core.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index a3e7c8798381..d8f28c6fe3a3 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2559,7 +2559,22 @@ EXPORT_SYMBOL(rproc_free);
  */
 void rproc_put(struct rproc *rproc)
 {
-	module_put(rproc->dev.parent->driver->owner);
+	struct platform_device *cluster_pdev;
+
+	if (rproc->dev.parent->driver) {
+		module_put(rproc->dev.parent->driver->owner);
+	} else {
+		/*
+		 * If the remoteproc's parent does not have a driver,
+		 * driver is associated with the cluster.
+		 */
+		cluster_pdev = of_find_device_by_node(rproc->dev.parent->of_node->parent);
+		if (cluster_pdev) {
+			module_put(cluster_pdev->dev.driver->owner);
+			put_device(&cluster_pdev->dev);
+		}
+	}
+
 	put_device(&rproc->dev);
 }
 EXPORT_SYMBOL(rproc_put);
-- 
2.25.1