Now that all in-tree ops-locked drivers have been converted to
ndo_set_rx_mode_async, add a warning in register_netdevice to catch
any remaining or newly added drivers that use ndo_set_rx_mode with
ops locking. This ensures future driver authors are guided toward
the async path.

Also route ops-locked devices through dev_rx_mode_work even if they
lack rx_mode NDOs, to ensure netdev_ops_assert_locked() does not fire
on the legacy path where only RTNL is held.

Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
---
 net/core/dev.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index d50d6dc6ac1f..187cd7b5074f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9778,7 +9778,8 @@ void __dev_set_rx_mode(struct net_device *dev)
 	if (!netif_up_and_present(dev))
 		return;
 
-	if (ops->ndo_set_rx_mode_async || ops->ndo_change_rx_flags) {
+	if (ops->ndo_set_rx_mode_async || ops->ndo_change_rx_flags ||
+	    netdev_need_ops_lock(dev)) {
 		queue_work(rx_mode_wq, &dev->rx_mode_work);
 		return;
 	}
@@ -11470,6 +11471,11 @@ int register_netdevice(struct net_device *dev)
 		goto err_uninit;
 	}
 
+	if (netdev_need_ops_lock(dev) &&
+	    dev->netdev_ops->ndo_set_rx_mode &&
+	    !dev->netdev_ops->ndo_set_rx_mode_async)
+		netdev_WARN(dev, "ops-locked drivers should use ndo_set_rx_mode_async\n");
+
 	ret = netdev_do_alloc_pcpu_stats(dev);
 	if (ret)
 		goto err_uninit;
-- 
2.53.0