Re: [PATCH net] net: phy: mdio_device: leave PHY reset deasserted on unregister

[Andrew Lunn <andrew@lunn.ch>]

On Wed, May 20, 2026 at 10:53:04PM +0000, Leonardo Mörlein wrote:
> > I'm wondering if we are fixing the wrong thing here.
> 
> In general, I see two options to fix this. Either we fix the
> tear down or we fix the setup of the device.

Can we take a step back, and look at your actual hardware. What is the
state of the hardware when Linux boots, but before the MDIO bus is
enumerated?

Is the GPIO is configured as an input, and there is a resistor keeping
the PHY out of reset?

Is the GPIO configured as an output with the reset not asserted, by
the bootloader?

Maybe when we probe the PHY we need to ask the GPIO subsystem how the
GPIO is configured. On unregistered of the PHY we need to put the GPIO
back into that state?

> Currently, it seems that this case only occurs when the kernel
> leaves the reset asserted. The bootloader initially leaves the
> reset deasserted, at least for my current hardware.

Are you sure about this? Maybe it is simply an input by default, with
a resistor pulling the reset line the right way?

	Andrew