Re: [PATCH iwl-next v2] ice: Disable Cage Max Power override

[Ido Schimmel <idosch@idosch.org>]

On Fri, Aug 25, 2023 at 11:01:07AM +0000, Drewek, Wojciech wrote:
> CC: Ido
> 
> > -----Original Message-----
> > From: Jakub Kicinski <kuba@kernel.org>
> > Sent: czwartek, 24 sierpnia 2023 17:32
> > To: Drewek, Wojciech <wojciech.drewek@intel.com>
> > Cc: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>
> > Subject: Re: [PATCH iwl-next v2] ice: Disable Cage Max Power override
> > 
> > On Thu, 24 Aug 2023 10:54:59 +0200 Wojciech Drewek wrote:
> > > NVM module called "Cage Max Power override" allows to
> > > change max power in the cage. This can be achieved
> > > using external tools. The responsibility of the ice driver is to
> > > go back to the default settings whenever port split is done.
> > > This is achieved by clearing Override Enable bit in the
> > > NVM module. Override of the max power is disabled so the
> > > default value will be used.
> > 
> > Can you say more? We have ETHTOOL_MSG_MODULE_GET / SET, sounds like
> > something we could quite easily get ethtool to support?
> 
> So you're suggesting that ethtool could support setting the maximum power in the cage? 
> Something like:
>  - new "--set-module" parameter called "power-max"
>  - new "--get-module" parameters: "power-max-allowed", "power-min-allowed" indicating limitations reported by the HW.
> 
> About the patch itself, it's only about restoration of the default settings upon port split. Those might be overwritten by 
> Intel's external tools.

Can you please explain why this setting needs to be changed in the first
place and why it needs to be restored to the default on port split?