Re: [PATCH 6/6] arm64: dts: allwinner: a523: x96qpro+: enable Ethernet support

Andrew Lunn <[email protected]> Tue, 4 Aug 2026 16:44:31 +0200

Newsgroups	dev.linux.lists.linux-sunxi,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.netdev
Message-ID	<[email protected]>

On Tue, Aug 04, 2026 at 11:11:04AM +0800, Chen-Yu Tsai wrote:
> On Tue, Aug 4, 2026 at 10:53 AM Andrew Lunn <[email protected]> wrote:
> >
> > > +&gmac1 {
> > > +     clocks = <&ccu CLK_BUS_EMAC1>, <&ccu CLK_MBUS_EMAC1>;
> > > +     pinctrl-names = "default";
> > > +     pinctrl-0 = <&rgmii1_pins>;
> > > +     phy-mode = "rgmii-id";
> > > +     phy-handle = <&ext_rgmii_phy>;
> > > +     phy-supply = <&reg_cldo3>;
> > > +
> > > +     tx-internal-delay-ps = <200>;
> > > +     rx-internal-delay-ps = <500>;
> >
> > 500ns is quite big. How did you come to this value? Do you have the
> > schematic & gerber files? Does the lines look unbalanced?
> 
> Unit is ps, not ns.

Yes, sorry, wrong units. But still 500ps is very big. You have the PHY
adding 2ns, due to rgmii-id, and you add another 500ps?

       Andrew