From bed7992daee2be780efc23bb87464dffca94faa9 Mon Sep 17 00:00:00 2001
From: Wong Vee Khee <vee.khee.wong@intel.com>
Date: Sun, 15 Nov 2020 15:42:10 +0800
Subject: [PATCH] net: stmmac: Use rtnl_lock/unlock on
 netif_set_real_num_rx_queues() call
Git-commit: 8e5debed39017836a850c6c7bfacc93299d19bad
Patch-mainline: v5.10-rc5
References: git-fixes

Fix an issue where dump stack is printed on suspend resume flow due to
netif_set_real_num_rx_queues() is not called with rtnl_lock held().

Fixes: 686cff3d7022 ("net: stmmac: Fix incorrect location to set real_num_rx|tx_queues")
Reported-by: Christophe ROULLIER <christophe.roullier@st.com>
Tested-by: Christophe ROULLIER <christophe.roullier@st.com>
Cc: Alexandre TORGUE <alexandre.torgue@st.com>
Reviewed-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Wong Vee Khee <vee.khee.wong@intel.com>
Link: https://lore.kernel.org/r/20201115074210.23605-1-vee.khee.wong@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index c865ae9c9e64..7eb568a12a03 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4588,6 +4588,7 @@ int stmmac_resume(struct device *dev)
 			stmmac_mdio_reset(priv->mii);
 	}
 
+	rtnl_lock();
 	mutex_lock(&priv->lock);
 
 	stmmac_reset_queues_param(priv);
@@ -4601,6 +4602,7 @@ int stmmac_resume(struct device *dev)
 	stmmac_enable_all_queues(priv);
 
 	mutex_unlock(&priv->lock);
+	rtnl_unlock();
 
 	if (!device_may_wakeup(priv->device)) {
 		rtnl_lock();
-- 
2.16.4