Re: [PATCH net-next v7 15/16] net: ethtool: ts: Let the active time stamping layer be selectable

[Köry Maincent]

On Wed, 22 Nov 2023 10:01:42 -0800
Jakub Kicinski <kuba@xxxxxxxxxx> wrote:

> On Wed, 22 Nov 2023 18:55:17 +0200 Vladimir Oltean wrote:
> > > Well, ethtool has been the catch all for a lot of random things
> > > for the longest time. The question is whether we want to extend
> > > ETHTOOL_GET_TS_INFO or add a third API somewhere else. And if we
> > > do - do we also duplicate the functionality of ETHTOOL_GET_TS_INFO
> > > (i.e. getting capabilities)?
> > > 
> > > My vote is that keeping it in ethtool is less bad than 3rd API.    
> > 
> > With SIOCSHWTSTAMP also implemented by CAN (and presumably also by
> > wireless in the future), I do wonder whether ethtool is the right place
> > for the netlink conversion.  
> 
> ethtool currently provides the only way we have to configure ring
> length, ring count, RSS, UDP tunnels etc.
> 
> It's a matter of taste, IMO ethtool is a bit of a lost cause already
> and keeping things together (ethtool already has TS_INFO) is cleaner
> than spreading them around.
> 
> > I wouldn't suggest duplicating ETHTOOL_GET_TS_INFO towards the netdev
> > netlink family.  
> 
> FTR so far the netdev family is all about SW configuration. We should
> probably keep it that way, so it doesn't become ginormous. It's easy
> enough to create a new family, if needed.

So, do we have a consensus? Vlad, do you agree on putting all under ethtool?

ETHTOOL_GET_TS_INFO will be in charge of replacing the SIOCGHWSTAMP
implementation. Need to add ETHTOOL_A_TSINFO_PHC_INDEX
ETHTOOL_A_TSINFO_QUALIFIER to the request.

ETHTOOL_GET_TS_INFO will list all the hwtstamp provider (aka "{phc_index,
qualifier}") through the dumpit callback. I will add a filter to be able to
list only the hwtstamp provider of one netdev.

ETHTOOL_SET_TS_INFO will be in charge of replacing the SIOCSHWSTAMP
implementation.

Is that ok for you?

Regards,
-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com