[U-Boot] Design principles (was: Re: [PATCH] net, fec_mxc: use mac address stored in env before looking in eeprom)

[Detlev Zundel]

Hi Wolfgang,

> Dear Detlev Zundel,
>
> In message <m2tys4k0c8.fsf at ohwell.denx.de> you wrote:
>> 
>> > The question to me is why fec_probe() is called at all, even in cases
>> > where U-Boot does not use any network related commands. This is IMO
>> > wrong. Eventually somebody comes up with patches to fix this?
>> 
>> As I said before, this is documented in doc/README.drivers.eth.  If you
>> want to change this, then maybe one should first fix the documentation
>
> I think the documentation should be changed when the code gets
> changed, not sooner nor later.

I'd much rather write up what I want to see in code than to document the
mess we have in some drivers, but as you keep saying - YMMV.

Actually the existance of a design document shows me that this thought
is not so wild as it sounds.

>> to know what is actually wanted.  I certainly have lost track of what is
>> wanted and what is sensible.
>
> We do not want to touch interfaces that we don't use. If we don't use
> Ethernet in U-Boot, there is no need to probe or initialize it.

Ok, I still don't get it.  Is this "we do not touch interfaces" a truth
not to be questioned or is it the essence of other goals we want to
achieve summed up in a nice fashion?

Because what I still fail to see is how writing 6 bytes into an SRAM
area is "touching a device".  Yet the absence of this code means that
there is no working solution at all to the problem at hand as you may
well know.

So can you please enlighten me why as to how initializing SRAM is
"touching a device" - or why exactly you oppose this so strict.

Thanks
  Detlev

-- 
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