[PATCH] net: usb: enable the work after stop usbnet by ip down/up

From: Jun Miao
Date: Tue Jul 08 2025 - 04:15:47 EST


From: Zqiang <qiang.zhang@xxxxxxxxx>

Oleksij reported that:
The smsc95xx driver fails after one down/up cycle, like this:
$ nmcli device set enu1u1 managed no
$ p a a 10.10.10.1/24 dev enu1u1
$ ping -c 4 10.10.10.3
$ ip l s dev enu1u1 down
$ ip l s dev enu1u1 up
$ ping -c 4 10.10.10.3
The second ping does not reach the host. Networking also fails on other interfaces.

Enable the work by replacing the disable_work_sync() with cancel_work_sync().

[Jun Miao: completely write the commit changelog]

Fixes: 2c04d279e857 ("net: usb: Convert tasklet API to new bottom half workqueue mechanism")
Reported-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Tested-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxx>
Signed-off-by: Jun Miao <jun.miao@xxxxxxxxx>
---
drivers/net/usb/usbnet.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 9564478a79cc..6a3cca104af9 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -861,14 +861,14 @@ int usbnet_stop (struct net_device *net)
/* deferred work (timer, softirq, task) must also stop */
dev->flags = 0;
timer_delete_sync(&dev->delay);
- disable_work_sync(&dev->bh_work);
+ cancel_work_sync(&dev->bh_work);
cancel_work_sync(&dev->kevent);

/* We have cyclic dependencies. Those calls are needed
* to break a cycle. We cannot fall into the gaps because
* we have a flag
*/
- disable_work_sync(&dev->bh_work);
+ cancel_work_sync(&dev->bh_work);
timer_delete_sync(&dev->delay);
cancel_work_sync(&dev->kevent);

--
2.32.0