Re: [PATCH] arm64: dts: renesas: white-hawk-cpu: Move avb0 reset gpio to mdio node

["Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>]

Hello Geert and Marek,

On 2024-08-22 15:56:44 +0200, Geert Uytterhoeven wrote:
> Hi Marek,
> 
> On Fri, Aug 2, 2024 at 7:16 PM Marek Vasut <marex@denx.de> wrote:
> > On 8/2/24 10:33 AM, Geert Uytterhoeven wrote:
> > > What is your stance on this?
> 
> > > On Thu, Jul 4, 2024 at 5:26 PM Niklas Söderlund
> > > <niklas.soderlund+renesas@ragnatech.se> wrote:
> > >> When creating a dedicated mdio node to describe the bus the gpio reset
> > >> property was erroneously left in the phy node. The reason for adding
> > >> mdio nodes on WhiteHawk was to ensure the PHYs where reset before they
> > >> were probed, keeping the property in the phy node prevented this.
> >
> > If the PHYs should be reset before they are probed, that is something
> > the PHY driver should take care of, right ? The PHY driver can bind to
> > the PHY via compatible string. Does the PHY driver not reset the PHYs ?
> 
> AFAIK, there is no requirement to reset the PHY before it is probed.
> However, the reset signal may be in asserted state when the PHY is
> probed (e.g. after unbind from the Ethernet driver, or during kexec).
> Identifying the PHY by reading the ID register requires deasserting
> the reset first.

Did we reach consensus on this? My primary motivation for this was to 
align it what is done for the other AVB instances on WhiteHawk, which do 
have the reset-gpios property in the mdio node and not the phy node.

As having a mdio node at all is a new-ish thing for AVB as this was
needed or the mv88q2110 PHYs connected to the other AVBs to function. If 
we are happy to have this here for AVB0 I will drop this patch.

-- 
Kind Regards,
Niklas Söderlund