Re: [PATCH net v1 1/1] net: usb: asix: forbid runtime PM to avoid PM/MDIO + RTNL deadlock

On Wed, Sep 17, 2025 at 11:54:57AM +0200, Oleksij Rempel wrote:

Forbid USB runtime PM (autosuspend) for AX88772* in bind.

[...]

With autosuspend active, resume paths may require calling phylink/phylib
(caller must hold RTNL) and doing MDIO I/O. Taking RTNL from a USB PM
resume can deadlock (RTNL may already be held), and MDIO can attempt a
runtime-wake while the USB PM lock is held.

FWIW, for smsc95xx.c, the MDIO deadlock issue was resolved by commit
7b960c967f2a ("usbnet: smsc95xx: Fix deadlock on runtime resume").
I would assume that something similar would be possible for
asix_devices.c as well.

Thanks,

Lukas