This is a note to let you know that I've just added the patch titled net: stmmac: delete the eee_ctrl_timer after napi disabled to the 5.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-stmmac-delete-the-eee_ctrl_timer-after-napi-disabled.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Dec 19 11:38:44 AM CET 2020 From: Fugang Duan <fugang.duan@xxxxxxx> Date: Mon, 7 Dec 2020 18:51:40 +0800 Subject: net: stmmac: delete the eee_ctrl_timer after napi disabled 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); Patches currently in stable-queue which might be from fugang.duan@xxxxxxx are queue-5.9/net-stmmac-free-tx-skb-buffer-in-stmmac_resume.patch queue-5.9/net-stmmac-overwrite-the-dma_cap.addr64-according-to-hw-design.patch queue-5.9/net-stmmac-start-phylink-instance-before-stmmac_hw_setup.patch queue-5.9/net-stmmac-delete-the-eee_ctrl_timer-after-napi-disabled.patch queue-5.9/net-stmmac-increase-the-timeout-for-dma-reset.patch