[PATCH net v1 1/1] net: usb: asix: ax88772: drop phylink use in PM to avoid MDIO runtime PM wakeups

Oleksij Rempel
2025-09-08T11:26:36Z

Drop phylink_{suspend,resume}() from ax88772 PM callbacks.

MDIO bus accesses have their own runtime-PM handling and will try to
wake the device if it is suspended. Such wake attempts must not happen
from PM callbacks while the device PM lock is held. Since phylink
{sus|re}sume may trigger MDIO, it must not be called in PM context.

No extra phylink PM handling is required for this driver:
- .ndo_open/.ndo_stop control the phylink start/stop lifecycle.
- ethtool/phylib entry points run in process context, not PM.
- phylink MAC ops program the MAC on link changes after resume.

Fixes: e0bffe3e6894 ("net: asix: ax88772: migrate to phylink")
Reported-by: Hubert Wiśniewski <hubert.wisniewski.25632@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
drivers/net/usb/asix_devices.c | 13 -------------
1 file changed, 13 deletions(-)

diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c
index 792ddda1ad49..1e8f7089f5e8 100644
--- a/drivers/net/usb/asix_devices.c
+++ b/drivers/net/usb/asix_devices.c
@@ -607,15 +607,8 @@ static const struct net_device_ops ax88772_netdev_ops = {

static void ax88772_suspend(struct usbnet *dev)
{
- struct asix_common_private *priv = dev->driver_priv;
u16 medium;

- if (netif_running(dev->net)) {
- rtnl_lock();
- phylink_suspend(priv->phylink, false);
- rtnl_unlock();
- }
-
/* Stop MAC operation */
medium = asix_read_medium_status(dev, 1);
medium &= ~AX_MEDIUM_RE;
@@ -644,12 +637,6 @@ static void ax88772_resume(struct usbnet *dev)
for (i = 0; i < 3; i++)
if (!priv->reset(dev, 1))
break;
-
- if (netif_running(dev->net)) {
- rtnl_lock();
- phylink_resume(priv->phylink);
- rtnl_unlock();
- }
}

static int asix_resume(struct usb_interface *intf)
--
2.47.3