This is a note to let you know that I've just added the patch titled net: stmmac: free tx skb buffer in stmmac_resume() 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-free-tx-skb-buffer-in-stmmac_resume.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 18:51:39 +0800 Subject: net: stmmac: free tx skb buffer in stmmac_resume() From: Fugang Duan <fugang.duan@xxxxxxx> [ Upstream commit 4ec236c7c51f89abb0224a4da4a6b77f9beb6600 ] When do suspend/resume test, there have WARN_ON() log dump from stmmac_xmit() funciton, the code logic: entry = tx_q->cur_tx; first_entry = entry; WARN_ON(tx_q->tx_skbuff[first_entry]); In normal case, tx_q->tx_skbuff[txq->cur_tx] should be NULL because the skb should be handled and freed in stmmac_tx_clean(). But stmmac_resume() reset queue parameters like below, skb buffers may not be freed. tx_q->cur_tx = 0; tx_q->dirty_tx = 0; So free tx skb buffer in stmmac_resume() to avoid warning and memory leak. log: [ 46.139824] ------------[ cut here ]------------ [ 46.144453] WARNING: CPU: 0 PID: 0 at drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:3235 stmmac_xmit+0x7a0/0x9d0 [ 46.154969] Modules linked in: crct10dif_ce vvcam(O) flexcan can_dev [ 46.161328] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 5.4.24-2.1.0+g2ad925d15481 #1 [ 46.170369] Hardware name: NXP i.MX8MPlus EVK board (DT) [ 46.175677] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 46.180465] pc : stmmac_xmit+0x7a0/0x9d0 [ 46.184387] lr : dev_hard_start_xmit+0x94/0x158 [ 46.188913] sp : ffff800010003cc0 [ 46.192224] x29: ffff800010003cc0 x28: ffff000177e2a100 [ 46.197533] x27: ffff000176ef0840 x26: ffff000176ef0090 [ 46.202842] x25: 0000000000000000 x24: 0000000000000000 [ 46.208151] x23: 0000000000000003 x22: ffff8000119ddd30 [ 46.213460] x21: ffff00017636f000 x20: ffff000176ef0cc0 [ 46.218769] x19: 0000000000000003 x18: 0000000000000000 [ 46.224078] x17: 0000000000000000 x16: 0000000000000000 [ 46.229386] x15: 0000000000000079 x14: 0000000000000000 [ 46.234695] x13: 0000000000000003 x12: 0000000000000003 [ 46.240003] x11: 0000000000000010 x10: 0000000000000010 [ 46.245312] x9 : ffff00017002b140 x8 : 0000000000000000 [ 46.250621] x7 : ffff00017636f000 x6 : 0000000000000010 [ 46.255930] x5 : 0000000000000001 x4 : ffff000176ef0000 [ 46.261238] x3 : 0000000000000003 x2 : 00000000ffffffff [ 46.266547] x1 : ffff000177e2a000 x0 : 0000000000000000 [ 46.271856] Call trace: [ 46.274302] stmmac_xmit+0x7a0/0x9d0 [ 46.277874] dev_hard_start_xmit+0x94/0x158 [ 46.282056] sch_direct_xmit+0x11c/0x338 [ 46.285976] __qdisc_run+0x118/0x5f0 [ 46.289549] net_tx_action+0x110/0x198 [ 46.293297] __do_softirq+0x120/0x23c [ 46.296958] irq_exit+0xb8/0xd8 [ 46.300098] __handle_domain_irq+0x64/0xb8 [ 46.304191] gic_handle_irq+0x5c/0x148 [ 46.307936] el1_irq+0xb8/0x180 [ 46.311076] cpuidle_enter_state+0x84/0x360 [ 46.315256] cpuidle_enter+0x34/0x48 [ 46.318829] call_cpuidle+0x18/0x38 [ 46.322314] do_idle+0x1e0/0x280 [ 46.325539] cpu_startup_entry+0x24/0x40 [ 46.329460] rest_init+0xd4/0xe0 [ 46.332687] arch_call_rest_init+0xc/0x14 [ 46.336695] start_kernel+0x420/0x44c [ 46.340353] ---[ end trace bc1ee695123cbacd ]--- Fixes: 47dd7a540b8a0 ("net: add support for STMicroelectronics Ethernet controllers.") 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 | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1530,6 +1530,19 @@ static void dma_free_tx_skbufs(struct st } /** + * stmmac_free_tx_skbufs - free TX skb buffers + * @priv: private structure + */ +static void stmmac_free_tx_skbufs(struct stmmac_priv *priv) +{ + u32 tx_queue_cnt = priv->plat->tx_queues_to_use; + u32 queue; + + for (queue = 0; queue < tx_queue_cnt; queue++) + dma_free_tx_skbufs(priv, queue); +} + +/** * free_dma_rx_desc_resources - free RX dma desc resources * @priv: private structure */ @@ -5183,6 +5196,7 @@ int stmmac_resume(struct device *dev) stmmac_reset_queues_param(priv); + stmmac_free_tx_skbufs(priv); stmmac_clear_descriptors(priv); stmmac_hw_setup(ndev, false); 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