Re: [PATCH net-next 3/3] nfp: devlink: allow flashing the device via devlink

[Florian Fainelli <f.fainelli@gmail.com>]

On 2/19/2019 4:49 PM, Jakub Kicinski wrote:
> On Tue, 19 Feb 2019 10:19:42 +0100, Jiri Pirko wrote:
>> Fri, Feb 15, 2019 at 04:44:29PM CET, jakub.kicinski@netronome.com wrote:
>>> On Fri, 15 Feb 2019 11:15:14 +0100, Jiri Pirko wrote:  
>>>>> static const struct ethtool_ops nfp_net_ethtool_ops = {    
>>>>
>>>> Why don't you use the compat fallback? I think you should.  
>>>
>>> You and Michal both asked the same so let me answer the first to ask :)
>>> - if devlink is built as a module the fallback is not reachable.  
>>
>> So the fallback is not really good as you can't use it for real drivers
>> anyway. Odd. Maybe we should compile devlink in without possibility to
>> have it as module.
> 
> Ack, I'll make devlink a bool.

Meh how about those poor and memory constrained embedded systems?
Ideally ethtool should/could have been modular as well, but that ship
has now sailed.

> 
> I need a little extra time, I forgot that nfp's flower offload still
> doesn't register all ports (using your port flavour infrastructure).
> 

We have had similar issues with PHYLIB before where we wanted
net/core/ethtool.c to be able to call into generic PHYLIB functions to
obtain PHY statistics, an inline helper that de-references the PHY
device's driver function pointers solved that (look for
phy_ethtool_get_{strings,sset,stats}) while letting PHYLIB remain modular.

devlink_compat_flash_update() is a bit big to be inlined, but why not?

If we make sure we always provide a devlink_mutex and devlink_list that
symbols such that this builds wheter CONFIG_DEVLINK=y|m then everything
else can be determined at runtime whether devlink.ko is loaded or not.

Does that make sense?
-- 
Florian