[PATCH 5.9 17/49] net: stmmac: delete the eee_ctrl_timer after napi disabled

[Greg Kroah-Hartman]

From: Fugang Duan <fugang.duan@xxxxxxx>

[ Upstream commit 5f58591323bf3f342920179f24515935c4b5fd60 ]

There have chance to re-enable the eee_ctrl_timer and fire the timer
in napi callback after delete the timer in .stmmac_release(), which
introduces to access eee registers in the timer function after clocks
are disabled then causes system hang. Found this issue when do
suspend/resume and reboot stress test.

It is safe to delete the timer after napi disabled and disable lpi mode.

Fixes: d765955d2ae0b ("stmmac: add the Energy Efficient Ethernet support")
Signed-off-by: Fugang Duan <fugang.duan@xxxxxxx>
Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2893,9 +2893,6 @@ static int stmmac_release(struct net_dev
 	struct stmmac_priv *priv = netdev_priv(dev);
 	u32 chan;
 
-	if (priv->eee_enabled)
-		del_timer_sync(&priv->eee_ctrl_timer);
-
 	if (device_may_wakeup(priv->device))
 		phylink_speed_down(priv->phylink, false);
 	/* Stop and disconnect the PHY */
@@ -2914,6 +2911,11 @@ static int stmmac_release(struct net_dev
 	if (priv->lpi_irq > 0)
 		free_irq(priv->lpi_irq, dev);
 
+	if (priv->eee_enabled) {
+		priv->tx_path_in_lpi_mode = false;
+		del_timer_sync(&priv->eee_ctrl_timer);
+	}
+
 	/* Stop TX/RX DMA and clear the descriptors */
 	stmmac_stop_all_dma(priv);
 
@@ -5077,6 +5079,11 @@ int stmmac_suspend(struct device *dev)
 	for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 		del_timer_sync(&priv->tx_queue[chan].txtimer);
 
+	if (priv->eee_enabled) {
+		priv->tx_path_in_lpi_mode = false;
+		del_timer_sync(&priv->eee_ctrl_timer);
+	}
+
 	/* Stop TX/RX DMA */
 	stmmac_stop_all_dma(priv);