[PATCH net 7/7] net: hibmcge: fix multiple phy_stop() issue

Jijie Shao
2025-04-02T13:46:07Z

After detecting the np_link_fail exception,
the driver attempts to fix the exception by
using phy_stop() and phy_start() in the scheduled task.

However, hbg_fix_np_link_fail() and .ndo_stop()
may be concurrently executed. As a result,
phy_stop() is executed twice, and the following Calltrace occurs:

hibmcge 0000:84:00.2 enp132s0f2: Link is Down
hibmcge 0000:84:00.2: failed to link between MAC and PHY, try to fix...
------------[ cut here ]------------
called from state HALTED
WARNING: CPU: 71 PID: 23391 at drivers/net/phy/phy.c:1503 phy_stop...
...
pc : phy_stop+0x138/0x180
lr : phy_stop+0x138/0x180
sp : ffff8000c76bbd40
x29: ffff8000c76bbd40 x28: 0000000000000000 x27: 0000000000000000
x26: ffff2020047358c0 x25: ffff202004735940 x24: ffff20200000e405
x23: ffff2020060e5178 x22: ffff2020060e4000 x21: ffff2020060e49c0
x20: ffff2020060e5170 x19: ffff20202538e000 x18: 0000000000000020
x17: 0000000000000000 x16: ffffcede02e28f40 x15: ffffffffffffffff
x14: 0000000000000000 x13: 205d313933333254 x12: 5b5d393430303233
x11: ffffcede04555958 x10: ffffcede04495918 x9 : ffffcede0274fee0
x8 : 00000000000bffe8 x7 : c0000000ffff7fff x6 : 0000000000000001
x5 : 00000000002bffa8 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff20202e429480
Call trace:
phy_stop+0x138/0x180
hbg_fix_np_link_fail+0x4c/0x90 [hibmcge]
hbg_service_task+0xfc/0x148 [hibmcge]
process_one_work+0x180/0x398
worker_thread+0x210/0x328
kthread+0xe0/0xf0
ret_from_fork+0x10/0x20
---[ end trace 0000000000000000 ]---

This patch adds the rtnl_lock to hbg_fix_np_link_fail()
to ensure that other operations are not performed concurrently.
In addition, np_link_fail exception can be fixed
only when the PHY is link.

Fixes: e0306637e85d ("net: hibmcge: Add support for mac link exception handling feature")
Signed-off-by: Jijie Shao <shaojijie@huawei.com>
---
drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c b/drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c
index f29a937ad087..42b0083c9193 100644
--- a/drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c
+++ b/drivers/net/ethernet/hisilicon/hibmcge/hbg_mdio.c
@@ -2,6 +2,7 @@
// Copyright (c) 2024 Hisilicon Limited.

#include <linux/phy.h>
+#include <linux/rtnetlink.h>
#include "hbg_common.h"
#include "hbg_hw.h"
#include "hbg_mdio.h"
@@ -133,12 +134,17 @@ void hbg_fix_np_link_fail(struct hbg_priv *priv)
{
struct device *dev = &priv->pdev->dev;

+ rtnl_lock();
+
if (priv->stats.np_link_fail_cnt >= HBG_NP_LINK_FAIL_RETRY_TIMES) {
dev_err(dev, "failed to fix the MAC link status\n");
priv->stats.np_link_fail_cnt = 0;
- return;
+ goto unlock;
}

+ if (!priv->mac.phydev->link)
+ goto unlock;
+
priv->stats.np_link_fail_cnt++;
dev_err(dev, "failed to link between MAC and PHY, try to fix...\n");

@@ -147,6 +153,9 @@ void hbg_fix_np_link_fail(struct hbg_priv *priv)
*/
hbg_phy_stop(priv);
hbg_phy_start(priv);
+
+unlock:
+ rtnl_unlock();
}

static void hbg_phy_adjust_link(struct net_device *netdev)
--
2.33.0