Re: [PATCH v2] net: fec: manage corner deferred probe condition

From: Andrew Lunn
Date: Sun Jan 15 2023 - 16:57:39 EST


On Sun, Jan 15, 2023 at 10:38:04PM +0100, Pierluigi Passaro wrote:
> For dual fec interfaces, external phys can only be configured by fec0.
> When the function of_mdiobus_register return -EPROBE_DEFER, the driver
> is lately called to manage fec1, which wrongly register its mii_bus as
> fec0_mii_bus.
> When fec0 retry the probe, the previous assignement prevent the MDIO bus
> registration.
> Use a static boolean to trace the orginal MDIO bus deferred probe and
> prevent further registrations until the fec0 registration completed
> succesfully.

The real problem here seems to be that fep->dev_id is not
deterministic. I think a better fix would be to make the mdio bus name
deterministic. Use pdev->id instead of fep->dev_id + 1. That is what
most mdiobus drivers use.

Andrew