[PATCH V2 4/5] net: stmmac: delete the eee_ctrl_timer after napi disabled

[Joakim Zhang <qiangqing.zhang@nxp.com>]

From: Fugang Duan <fugang.duan@nxp.com>

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@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 53c5d77eba57..03c6995d276a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2938,9 +2938,6 @@ static int stmmac_release(struct net_device *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 */
@@ -2959,6 +2956,11 @@ static int stmmac_release(struct net_device *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);
 
@@ -5185,6 +5187,11 @@ int stmmac_suspend(struct device *dev)
 	for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 		hrtimer_cancel(&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);
 
-- 
2.17.1