Jan Stary wrote:
> Here is the cpsw problem:
> 
> -cpsw0 at omsysc46: version 1.12 (0), address 90:59:af:82:2e:7e
> +cpsw0 at omsysc46: version 1.12 (0), address 00:00:00:00:00:00

I confirm this on beaglebone black but I'm not sure it's actually a
dtb bug, more on that below.

I could anyway DHCP and ping with great success with the zero address.


> > I reverted the change that switches from the 'old' cpsw switch driver
> > model to the 'new' one.  This should allow is to update the dtbs.
> 
> I don't know what the old/new model is,

I too am a bit confused, Patrick can you please clarify 'old' and 'new'?


Does it have to do with these two sibling fragments?

ethernet@0 {
        compatible = "ti,am335x-cpsw", "ti,cpsw";

switch@0 {
        compatible = "ti,am335x-cpsw-switch", "ti,cpsw-switch";

(Only the former is (currently) matched by OpenBSD if_cpsw.c.)


> but the version in this dtb breaks my bbb.

In a way it may be making things more correct, just not yet complete.

For one, both the dtb from Nov 1 snapshot miniroot-am335x-72.img and
Patrick's dtb have mac-address = [00 00 00 00 00 00]; for both slaves
(= PHYs). (Though I don't believe that this value is ever used.)

Working on the cpsw driver I was silently wondering where the nonzero
MAC on my beaglebone black comes from and I still don't know the answer.


Here's a boot log:

--8<-- Nov 1 snapshot miniroot
U-Boot SPL 2021.10 (Aug 13 2022 - 07:42:11 -0600)
Trying to boot from MMC1


U-Boot 2021.10 (Aug 13 2022 - 07:42:11 -0600)

CPU  : AM335X-GP rev 2.1
Model: TI AM335x BeagleBone Black
DRAM:  512 MiB
WDT:   Started with servicing (60s timeout)
NAND:  0 MiB
MMC:   OMAP SD/MMC: 0, OMAP SD/MMC: 1
Loading Environment from FAT... Unable to read "uboot.env" from mmc0:1... 
<ethaddr> not set. Validating first E-fuse MAC
Net:   eth2: ethernet@4a100000, eth3: usb_ether
Hit any key to stop autoboot:  0 
-->8--

Does "<ethaddr> not set. Validating first E-fuse MAC" mean that
U-Boot reads the fused MAC_ID0 from the am335x control module and
writes it into the CPSW registers?


Booting Patrick's U-Boot (MLO and u-boot.img) with the older snapshot
dtb I see the same message from U-Boot and cpsw0 has nonzero address.

After also copying Patrick's dtb to the memory card I still see the
same message from U-Boot but cpsw0 now has zero address.

After writing the full Nov 1 snapshot again and copying only the new dtb
over it I also see the message from U-Boot but cpsw0 again has zero address.

In all these tries, env print ethaddr in U-Boot always shows nonzero address.


As I understand the driver, cpsw0 will always have a zero address if
the "ti,cpsw" device tree node has either no child nodes at all or
none named "local-mac-address".

If a "local-mac-address" child node exists then that address is used.

(if_cpsw.c:364 cpsw_attach() calling cpsw_get_port_config() ff.)

Neither the snapshot dtb nor Patrick's dtb contain "local-mac-address" so
is U-Boot modifying only the older dtb (why!?) or what is going on here?


//Peter

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