[PATCH v6 02/16] firmware: arm_scmi: Unregister device notifier before IDR teardown

The requested-devices notifier looks up protocol fwnodes from the
active_protocols IDR. During remove, unregister the notifier before
releasing and destroying active_protocols so no notifier callback can race
with the IDR teardown.

Keep the bus notifier registered until after the protocol state is torn
down, matching the existing remove ordering for SCMI bus users.

Fixes: 53b8c25df708 ("firmware: arm_scmi: Add common notifier helpers")
Reported-by: Sashiko <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>
---
 drivers/firmware/arm_scmi/driver.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 1d1f5d25d773..52aff3aded4c 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -3401,6 +3401,9 @@ static void scmi_remove(struct platform_device *pdev)
 	list_del(&info->node);
 	mutex_unlock(&scmi_list_mutex);
 
+	blocking_notifier_chain_unregister(&scmi_requested_devices_nh,
+					   &info->dev_req_nb);
+
 	scmi_notification_exit(&info->handle);
 
 	mutex_lock(&info->protocols_mtx);
@@ -3411,8 +3414,6 @@ static void scmi_remove(struct platform_device *pdev)
 		of_node_put(child);
 	idr_destroy(&info->active_protocols);
 
-	blocking_notifier_chain_unregister(&scmi_requested_devices_nh,
-					   &info->dev_req_nb);
 	bus_unregister_notifier(&scmi_bus_type, &info->bus_nb);
 
 	/* Safe to free channels since no more users */

-- 
2.43.0