interconnect: Sanity check that node isn't already on list

Broken interconnect providers might add the same node multiple times or
in multiple providers, which causes strange errors as the provider's
node list is later traversed.

Detect that a node already has an associated provider, complain and
reject the addition of the node, to aid the developer.

Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Georgi Djakov <[email protected]>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 8a1e70e00876..fcb5d8eefb51 100644
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -959,6 +959,9 @@ EXPORT_SYMBOL_GPL(icc_link_destroy);
  */
 void icc_node_add(struct icc_node *node, struct icc_provider *provider)
 {
+	if (WARN_ON(node->provider))
+		return;
+
 	mutex_lock(&icc_lock);
 
 	node->provider = provider;