[U-Boot] [PATCH v3 0/2] sunxi: Enable EMAC on A83T boards using Realtek RTL8211E PHY

[Chen-Yu Tsai]

On Fri, May 3, 2019 at 5:49 PM Jagan Teki <jagan at amarulasolutions.com> wrote:
>
> On Fri, May 3, 2019 at 7:58 AM Chen-Yu Tsai <wens at kernel.org> wrote:
> >
> > From: Chen-Yu Tsai <wens at csie.org>
> >
> > Hi everyone,
> >
> > This series enables EMAC (Ethernet controller) on two A83T boards,
> > the Cubietruck Plus and Bananapi M3.
> >
> > This series is now based on sunxi/next, which has patches that convert
> > sun8i-emac to use the common CLK and DM_RESET framework.
> >
> > The two patches enable the sun8i-emac and Realtek PHY driver in their
>
> So, the U-Boot operates realtek than what Linux does via
> ethernet-phy-ieee802.3-c22 right? if someone add it in future it will
> override realtek since we have a dts compatible enabled it dts files
> already isn't it?

What? No. The PHY vendor and model are automatically detected by reading
the standard registers in the PHY. The compatible string is only used to
determine how to access the registers. c22 vs c45 define different ways
of accessing registers, as well as a larger address space for c45.

See https://www.totalphase.com/support/articles/200349206-MDIO-Background

By reading the vendor and model IDs, the system, be it Linux or U-boot,
can then go through the list of registered PHY drivers to find a match,
or fall back to some generic implementation.

It used to be you needed to enable the Realtek driver for gigabit links
to work properly, but that seems to have been fixed. Nevertheless, having
the specific driver enabled is better.

ChenYu