Re: [PATCH RESEND net-next v2 1/8] dt-bindings: net: dwmac-sun8i: Clean up clock delay chain descriptions

[Andrew Lunn <andrew@lunn.ch>]

On Sun, May 13, 2018 at 01:11:08PM -0700, Chen-Yu Tsai wrote:
> On Sun, May 13, 2018 at 1:05 PM, Andrew Lunn <andrew@lunn.ch> wrote:
> >> > Hi Chen-Yu
> >> >
> >> > Are these delays the MAC applies? Not the PHY. It would be good to
> >> > make it clear here these are MAC imposed delays.
> >>
> >> Yes these are applied on the MAC side. Being described in the device
> >> tree bindings for the MAC, I thought this was implied to be the case?
> >> Are there known exceptions?
> >
> > There is frequent confusion with this. Most of the time, the PHY does
> > the delay, not the MAC, based on the phy-mode. So the MAC doing it is
> > an exception in itself.
> >
> > Do you actually need these delays for the board you adding support
> > for? Does the PHY not support adding the needed delays? If you don't
> > need the delays, i would not even implement them.
> 
> Yes this is already used on the Bananapi M3. This patch merely reformats
> the description and adds a note saying this only applies to RGMII mode.

Yes, the current code is needed for the Bananapi M3. But you have
another patch which extends the code to support a smaller range. Do
you have a board which actually needs this? If not, i would not add
that new code.

     Andrew