Re: [PATCH] net: dsa: mt7530: fix null pointer dereferencing in port5 setup

[Chuanhong Guo]

Hi!

On Sat, Apr 4, 2020 at 11:08 PM Andrew Lunn <andrew@xxxxxxx> wrote:
> > > MT7530 tries to detect if 2nd GMAC is using a phy with phy-address 0 or 4.
> >
> > What if the 2nd GMAC connects to an external PHY on address 0 on a
> > different mdio-bus?
>
> In general, you using a phy-handle to cover such a situation. If there
> is a phy-handle, just use it.

If it's determining where switch mac5 is wired, a phy-handle is fine.
Here we are determining where exposed rgmii2 pins are wired.
It can be wired to switch mac5 or skip the switch mac completely
and connected to phy0/phy4.
Current driver is determining rgmii2 wiring on mt7530 using phy-handle
on *another unrelated ethernet node* which doesn't sound right.

-- 
Regards,
Chuanhong Guo