On Mon, Oct 21, 2024 at 03:27:18PM +0200, Andrew Lunn wrote: > > It is related to the RGMII delay. On sg2044, when the phy > > sets rx-delay, the interal mac is not set the same delay, > > so this is needed to be set. > > This is the wrong way to do it. Please look at how phy-mode should be > used, the four different "rgmii" values. Nearly everybody gets this > wrong, so there are plenty of emails from me in the netdev list about > how it should be done. > The phy-mode is alreay set to the "rgmii-id" and a rx delay is already set (a default tx delay is set by the phy driver). In the scenario the extra bit is used to fix 2ns difference between the sampling clock and data. It is more like an extra setting and the kernel can not handle it by only setting the phy-mode. This is draft dts patch for the sg2044 gmac. https://github.com/project-inochi/linux/commit/381cb6000044a89cb13d6d9c839e9bbc7b9d2e5a Regards, Inochi