[PATCH 5/5] arm64: dts: renesas: s4sk: Fix ethernet0 alias for rswitch

[Geert Uytterhoeven]

On Sat, Jan 18, 2025 at 12:14 PM Marek Vasut
<marek.vasut+renesas at mailbox.org> wrote:
> Each rswitch port TSNn has a dedicated MAC address assigned to it,
> so does AVB MAC. The MAC addresses for each rswitch port and AVB,
> four in total, are stored in the FPGA populated on the board and
> can be read out via I2C from bus i2c at e66e0000 address 0x70 offsets
> 0x58 for AVB and 0x60, 0x68, 0x70 for TSNn .
>
> There is no single MAC address assigned to the rswitch itself, there
> are three of them, one for each rswitch port. Instead of ethernet0
> alias for rswitch itself, describe alias ethernet0, ethernet1 for
> each enabled rswitch port. This allows U-Boot to insert MAC addresses
> from its environment variables ethaddr/eth1addr/eth2addr into each
> rswitch port nodes, so Linux can read and use one unique MAC address
> for each rswitch port.
>
> Note that it is unlikely this would break existing rswitch driver
> operation in the Linux kernel, because as of right now, the rswitch
> driver already calls of_get_ethdev_address() for each port to read
> out the MAC address out of each rswitch port DT node, and if that is
> missing, it falls back to MAC address settings read from the hardware
> itself, and if that also fails, it uses random MAC address.
>
> Fixes: 412f2224b3b6 ("arm64: dts: renesas: s4sk: Fix ethernet0 alias")
> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>

Reviewed-by: Geert Uytterhoeven <geert+renesas at glider.be>
i.e. will queue in renesas-devel for v6.15.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds