Re: [PATCH net-next RFC 7/7] bnxt_en: Add bnxt_en initial port params table and register it

[Jakub Kicinski <jakub.kicinski@netronome.com>]

On Wed, 5 Dec 2018 22:41:43 -0800, Michael Chan wrote:
> > > We do have a parameter in NVRAM that controls default WoL.  I think
> > > this is to expose that parameter so it can be set one way or the
> > > other. There are scenarios where Linux has not booted yet (and so
> > > there is no opportunity to run ethtool -s or any daemons yet) and this
> > > parameter will control whether the machine will wake up or not.  
> >
> > Isn't that set in BIOS/setup?  The config before any OS boots?  Because
> > the BMC or whatnot has to actually configure the board to power
> > appropriate things up.  Please clarify.  
> 
> It will be in the BIOS only for a LOM, I think.  For a NIC, it should
> be in the NIC's NVRAM.

This is all vague.  Could you please clearly state the use case.

> > And *if* it is proven this config is more than just setting the default
> > IMHO the setting belongs in the ethtool API.  We can't just add devlink
> > params for all existing config APIs just because it has persistence.  
> 
> I'm not sure I understand your point.  I believe the NIC firmware will
> set up the NIC's WoL setting right after power up based on this NVRAM
> parameter.  Similar to how the firmware will setup PCIe Gen2 or Gen3
> right after power up, for example.  

We have no PCIe config interface therefore the crutch of devlink params
was allowed there.  We *do* have an existing interface to configure WoL.

> So why would this belong to ethtool?  I understand the confusion that
> ethtool -s has a similar WoL setting.  But again, that's different.

Perhaps you're looking at this from firmware perspective?  FW NVM knob
== devlink param?

> This one is the power up setting that impacts whether a magic packet
> can or cannot wake up the system right after power up (before booting
> up to Linux or other OS).