[PATCH 1/8] net: phy: realtek: rtl8221: allow to configure SERDES mode

[Andrew Lunn]

> +#define RTL8221B_SERDES_OPTION_MODE_2500BASEX_SGMII	0
> +#define RTL8221B_SERDES_OPTION_MODE_HISGMII_SGMII	1
> +#define RTL8221B_SERDES_OPTION_MODE_2500BASEX		2

So what is 2500BASEX_SGMII? You cannot run SGMII at 2.5G, because
there is no way to repeat a symbol 2.5 times so that a 1G stream takes
up 2.5G bandwidth. The SGMII signalling also does not work at 2.5G.

Please add an explanation what this actually is.

       Andrew