Re: [PATCH 0/4] arm64: dts: rockchip: Add HINLINK H66K/H68K

[Erik Beck <xunil@tahomasoft.com>]

On Sat, 30 Aug 2025 18:20:50 -0400
Erik Beck <xunil@tahomasoft.com> wrote:

> > On Aug 30, 2025, at 17:30, Andrew Lunn <andrew@lunn.ch> wrote:
> > 
> >   
> >> 
> >> As I worked on my dts, I discovered that the 1Gb ethernet ports, using an
> >> RTL8211, don't support rgmii-id mode; only rgmii.
> >> (https://www.realtek.com/Product/Index?id=3976&cate_id=786).  
> > 
> > Which exact RTL8211 does the board use? You link to information for
> > the RTL8211FD(I)-CG, which i assume is supported in Linux as RTL8211F.  
> 
> Thanks Andrew; It isn't clear to me which specific variation it has. I'll
> take another look at the boot logs and see. The silkscreen on the chips are
> faint, but will look there too.

dmesg reports it is an RTL8211F.

> > 
> > https://elixir.bootlin.com/linux/v6.16.3/source/drivers/net/phy/realtek/realtek_main.c#L519
> > 
> > This indicates it supports all four RGMII modes. And in general, all
> > PHY drivers in Linux for RGMII PHYs support all four RGMII modes.
> >   
> >> Changing this makes a huge difference in the ethernet throughput speed.
> >> With rgmii-id mode specified, throughput is about 6.5 Mbs. Changing this
> >> to rgmii mode increases throughput to about 960 Mbs.  
> > 
> > Here is some more information about that the four RGMII modes mean,
> > and how you should use them in Linux:
> > 
> > https://elixir.bootlin.com/linux/v6.16.3/source/Documentation/devicetree/bindings/net/ethernet-controller.yaml#L264
> > 
> >    Andrew  
> 
> Thank you!
> > 
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