Hello Andrew,
On Tue, Jan 28, 2025 at 06:44:26PM +0100, Andrew Lunn wrote:
> > +&gmac1 {
> > + /* Uses a KSZ9031RNX phy */
> > + status = "okay";
> > + phy-mode = "rgmii";
> > +
> > + rxd0-skew-ps = <420>;
> > + rxd1-skew-ps = <420>;
> > + rxd2-skew-ps = <420>;
> > + rxd3-skew-ps = <420>;
> > + txen-skew-ps = <0>;
> > + txc-skew-ps = <1860>;
> > + rxdv-skew-ps = <420>;
> > + rxc-skew-ps = <1680>;
> > +};
>
> The convectional meaning of phy-mode 'rgmii' is that the PCB provides
> the 2ns delay. Here you are abusing the
>
> > + txc-skew-ps = <1860>;
> > + rxc-skew-ps = <1680>;
>
> To add these delays.
Ah, at some point I already knew that. Thanks for repeating that hint.
(Back then it was for
arch/arm64/boot/dts/rockchip/rk3568-qnap-ts433.dts.)
> Please test without these two lines, and change phy-mode to
> 'rgmii-id'. 1680 is rather low, so it might not work. Look for CRC
> errors for received packets.
I did an apt upgrade involving > 100 MB downloads with rgmii-id and
afterwards I had:
# ip -stats link show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAU
LT group default qlen 1000
link/ether ee:5f:09:22:72:da brd ff:ff:ff:ff:ff:ff
RX: bytes packets errors dropped missed mcast
158336739 113000 0 0 0 0
TX: bytes packets errors dropped carrier collsns
482481 5094 0 0 0 0
so that seems to be fine, right?
Best regards
Uwe
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