[PATCH 3/4] arm64: dts: rockchip: Add HINLINK H68K

[Erik Beck]

On Sat, 30 Aug 2025 18:21:18 -0400
Erik Beck <xunil at tahomasoft.com> wrote:

> > On Aug 30, 2025, at 17:38, Andrew Lunn <andrew at lunn.ch> wrote:
> > 
> >   
> >>   
> >>> +&gmac0 {
> >>> +    assigned-clocks = <&cru SCLK_GMAC0_RX_TX>, <&cru SCLK_GMAC0>;
> >>> +    assigned-clock-parents = <&cru SCLK_GMAC0_RGMII_SPEED>;
> >>> +    assigned-clock-rates = <0>, <125000000>;
> >>> +    clock_in_out = "output";
> >>> +    phy-handle = <&rgmii_phy0>;
> >>> +    phy-mode = "rgmii-id";  
> >> 
> >> Please change phy-mode here to "rgmii". This change will yield an
> >> ethernet speed throughput change of a factor of 100+.  
> > 
> > Rockchip by default do bad things with RGMII delays.
> > 
> >  tx_delay:
> >    description: Delay value for TXD timing.
> >    $ref: /schemas/types.yaml#/definitions/uint32
> >    minimum: 0
> >    maximum: 0x7F
> >    default: 0x30
> > 
> >  rx_delay:
> >    description: Delay value for RXD timing.
> >    $ref: /schemas/types.yaml#/definitions/uint32
> >    minimum: 0
> >    maximum: 0x7F
> >    default: 0x10
> > 
> > Try setting both of these to 0. And then use 'rgmii-id'.
> > 
> >    Andrew  
Setting both gmac0 and gmac1 to phy-mode=rgmii-id with tx/rx delay set to
<0x0> yields about a 7x improvement from ~6 Mbs (with phy-mode=rgmii-id and
tx/rx delay unset) to about 43 Mbps, which is still well below the ~950 Mbs
with phy-mode=rgmii and tx/rx delay unset.

Regards,

Erik

> 
> Thank you!
> > 
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