On Sat, Jan 18, 2025 at 12:14 PM Marek Vasut <marek.vasut+renesas@xxxxxxxxxxx> 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@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@xxxxxxxxxxx> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> 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@xxxxxxxxxxxxxx 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