Subject: Re: Lockup in phy_probe() for MDIO device (Broadcom's switch)

From: Andrew Lunn <[email-masked]>
Date: Thu, 30 Sep 2021 15:32:08 +0200

> I should also point out that as this b53 driver that is causing the
> problem only exists in OpenWRT, this is really a matter for OpenWRT
> developers rather than mainline which does not suffer this problem.
> I suspect that OpenWRT developers will not be happy with either of
> the two patches I've posted above - I suspect they are trying to
> support both DSA and swconfig approaches with a single DT. That can
> be made to work, but not with a PHYLIB driver being a wrapper around
> the swconfig stuff (precisely because there's no phy_device in this
> scenario.)
> 
> The only reason to patch mainline kernels would be to make them more
> robust, and maybe to also make an explicit statement about what isn't
> supported (having a phy_driver with its of_match_table member set.)

I agree with you here. This is an OpenWRT problem. We would hopefully
catch such a driver at review time and reject it. We could make it
more robust in mainline, but as you said, OpenWRT developers might not
actually like it more robust.

	 Andrew