Subject: [PATCH] net: mvneta: only do WoL speed down if the PHY is valid

From: Daniel González Cabanelas <[email-masked]>
Date: Thu, 21 May 2020 16:19:53 +0200

Previous patch:
 "net: mvneta: speed down the PHY, if WoL used, to save energy"

was causing a NULL pointer dereference when ethernet switches are
connected to mvneta, because they aren't handled directly as PHYs.

Fix it by restricting the mentioned patch for the PHY detected cases.

Reported-by: Andrew Lunn <[email-masked]>
Signed-off-by: Daniel González Cabanelas <[email-masked]>
---
 drivers/net/ethernet/marvell/mvneta.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 41d2a0eac..f9170bc93 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -3567,8 +3567,9 @@ static void mvneta_start_dev(struct mvneta_port *pp)
 
 	phylink_start(pp->phylink);
 
-	/* We may have called phy_speed_down before */
-	phy_speed_up(pp->dev->phydev);
+	if(pp->dev->phydev)
+		/* We may have called phy_speed_down before */
+		phy_speed_up(pp->dev->phydev);
 
 	netif_tx_start_all_queues(pp->dev);
 }
@@ -3577,7 +3578,7 @@ static void mvneta_stop_dev(struct mvneta_port *pp)
 {
 	unsigned int cpu;
 
-	if (device_may_wakeup(&pp->dev->dev))
+	if (pp->dev->phydev && device_may_wakeup(&pp->dev->dev))
 		phy_speed_down(pp->dev->phydev, false);
 
 	phylink_stop(pp->phylink);
-- 
2.26.2