RE: [PATCH net-next] dt-bindings: net: xilinx: document xilinx emaclite driver binding

[Radhey Shyam Pandey]

> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> Sent: Tuesday, May 31, 2022 12:40 AM
> To: Radhey Shyam Pandey <radheys@xxxxxxxxxx>; Radhey Shyam Pandey
> <radhey.shyam.pandey@xxxxxxx>; davem@xxxxxxxxxxxxx;
> edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx;
> robh+dt@xxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx;
> harini.katakam@xxxxxxx; michal.simek@xxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; git@xxxxxxx
> Subject: Re: [PATCH net-next] dt-bindings: net: xilinx: document xilinx emaclite
> driver binding
> 
> On 30/05/2022 15:21, Radhey Shyam Pandey wrote:
> >>
> >>> +        local-mac-address = [00 0a 35 00 00 00];
> >>
> >> Each device should get it's own MAC address, right? I understand you
> >> leave it for bootloader, then just fill it with 0.
> >
> > The emaclite driver uses of_get_ethdev_address() to get mac from DT.
> > i.e  'local-mac-address' if present in DT it will be read and this MAC
> > address is programmed in the MAC core. So I think it's ok to have a
> > user defined mac-address (instead of 0s) here in DT example?
> 
> And you want to program the same MAC address in every device in the world?
> How would that work?

I agree, for most of practical usecases mac address will be set by bootloader[1].
But just thinking for usecases where uboot can't read from non-volatile memory
user are still provided with option to set local-mac-address in DT and let linux
also configures it? Also see this in couple of other networking driver examples. 

cdns,macb.yaml:  local-mac-address: true
cdns,macb.yaml:            local-mac-address = [3a 0e 03 04 05 06];
brcm,systemport.yaml:        local-mac-address = [ 00 11 22 33 44 55 ];

In emaclite yaml - as it an example I will set it mac-address to 0 to align 
with common usecase.  local-mac-address = [00 00 00 00 00 00]

[1]: https://support.xilinx.com/s/article/53476

> 
> 
> 
> Best regards,
> Krzysztof