[PATCH v3] net: stmmac: fix 'ethtool -P' return -EBUSY

The permanent mac address should be available for query when the device
is not up.
NetworkManager, the system network daemon, uses 'ethtool -P' to obtain
the permanent address after the kernel start. When the network device
is not up, it will return the device busy error with 'ethtool -P'. At
that time, it is unable to access the Internet through the permanent
address by NetworkManager.
I think that the '.begin' is not used to check if the device is up.

Signed-off-by: Hao Chen <redacted>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index d0ce608b81c3..8fbb58c95507 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c

@@ -15,6 +15,7 @@
 #include <linux/phylink.h>
 #include <linux/net_tstamp.h>
 #include <asm/io.h>
+#include <linux/pm_runtime.h>
 
 #include "stmmac.h"
 #include "dwmac_dma.h"

@@ -412,8 +413,10 @@ static void stmmac_ethtool_setmsglevel(struct net_device *dev, u32 level)
 
 static int stmmac_check_if_running(struct net_device *dev)
 {
-	if (!netif_running(dev))
-		return -EBUSY;
+	struct stmmac_priv *priv = netdev_priv(dev);
+
+	pm_runtime_get_sync(priv->device);
+
 	return 0;
 }
 

-- 
2.20.1