Hi Andrew,
On Fri, 3 Jan 2025 at 21:34, Andrew Lunn <andrew@xxxxxxx> wrote:
>
> > +&gmac1 {
> > + clock_in_out = "output";
> > + phy-handle = <&rgmii_phy1>;
> > + phy-mode = "rgmii";
>
> rgmii is wrong. Please search the archives about this topic, it comes
> up every month. You need to remove the tx_delay and rx_delay
> properties, and use rgmii-id.
>
According to the RKRK3588 TRM-Part1 (section 25.6.11 Clock
Architecture), in RGMII mode,
the TX clock source is exclusively derived from the CRU (Clock Request Unit).
To dynamically adjust the timing alignment between TX/RX clocks and
data, delay lines are
integrated into both the TX and RX clock paths.
Register SYS_GRF_SOC_CON7[5:2] enables these delay lines,
while registers SYS_GRF_SOC_CON8[15:0] and SYS_GRF_SOC_CON9[15:0]
are used to configure the delay length for each path respectively.
Each delay line comprises 200 individual delay elements.
Therefore, it is necessary to configure both TX and RX delay values
appropriately
with phy-mode set as rgmii.
[1[ https://github.com/torvalds/linux/blob/master/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c#L1889-L1914
I have gone through a few of the archives about this topic
[2] https://lore.kernel.org/linux-rockchip/4fdcb631-16cd-d5f1-e2be-19ecedb436eb@xxxxxxxxxx/T/
Thanks
-Anand
