[PATCH 4.14 017/242] net: stmmac: free tx skb buffer in stmmac_resume()

Greg Kroah-Hartman
2020-12-28T16:28:27Z

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

[ 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@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 | 14 ++++++++++++++
1 file changed, 14 insertions(+)

--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1429,6 +1429,19 @@ 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
*/
@@ -4503,6 +4516,7 @@ int stmmac_resume(struct device *dev)
*/
priv->mss = 0;

+ stmmac_free_tx_skbufs(priv);
stmmac_clear_descriptors(priv);

stmmac_hw_setup(ndev, false);