Re: [PATCH net 0/4] net: phy: restore driver state after userspace MII resets

[James Hilliard]

On Fri, Nov 13, 2026 at 6:33 AM Andrew Lunn <andrew@xxxxxxx> wrote:
>
> On Fri, Nov 13, 2026 at 01:48:39AM -0700, James Hilliard wrote:
> > An MII ioctl reset needs to restore the PHY driver's configuration and
> > software state before the PHY worker can access the device again.
>
> The MII ioctl is a footgun. If you use it for writing registers, don't
> be surprised if bad things happen. Even reading registers can cause
> bad side effects, like missed interrupts.
>
> The whole design is broken, there is no fixing it, so we don't try to
> fix it.

Would it make sense to submit patches 1 and 2 as standalone fixes,
separate from the reset recovery changes?

The b44 patch removes a spinlock held across sleeping phylib/MDIO
operations, including ordinary register reads. The write-error patch
propagates MDIO failures and avoids updating cached settings or running
follow-up operations after a failed write.

These fixes are independent of each other and neither adds reset
recovery or attempts to make arbitrary register access safe.

>
> Sorry, but NACK.
>
>        Andrew