[PATCH 4.9 014/175] net: stmmac: delete the eee_ctrl_timer after napi disabled

Greg Kroah-Hartman
2020-12-28T12:59:44Z

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

[ 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@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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
@@ -1901,9 +1901,6 @@ static int stmmac_release(struct net_dev
{
struct stmmac_priv *priv = netdev_priv(dev);

- if (priv->eee_enabled)
- del_timer_sync(&priv->eee_ctrl_timer);
-
/* Stop and disconnect the PHY */
if (priv->phydev) {
phy_stop(priv->phydev);
@@ -1924,6 +1921,11 @@ 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 */
priv->hw->dma->stop_tx(priv->ioaddr);
priv->hw->dma->stop_rx(priv->ioaddr);
@@ -3503,6 +3505,11 @@ int stmmac_suspend(struct device *dev)

napi_disable(&priv->napi);

+ if (priv->eee_enabled) {
+ priv->tx_path_in_lpi_mode = false;
+ del_timer_sync(&priv->eee_ctrl_timer);
+ }
+
/* Stop TX/RX DMA */
priv->hw->dma->stop_tx(priv->ioaddr);
priv->hw->dma->stop_rx(priv->ioaddr);