RE: [RFC net-next 0/4] devlink: Add boot-time defaults

[Parav Pandit]

> From: Jiri Pirko <jiri@xxxxxxxxxxx>
> Sent: 12 May 2026 07:37 PM
> 
> Tue, May 12, 2026 at 03:48:32PM CEST, parav@xxxxxxxxxx wrote:
> >
> >> From: Jiri Pirko <jiri@xxxxxxxxxxx>
> >> Sent: 12 May 2026 02:16 PM
> >>
> >> Mon, May 11, 2026 at 08:21:37PM +0200, parav@xxxxxxxxxx wrote:
> >> >
> >> >> From: Mark Bloch <mbloch@xxxxxxxxxx>
> >> >> Sent: 10 May 2026 06:02 PM
> >> >>
> >> >
> >> >[..]
> >> >
> >> >> > I look at it from the perspective that from some CX generation,
> >> >> > switchdev mode should be default. So that is a device-based decision.
> >> >> > I believe as such it can optionally be permanenty configured (nv config)
> >> >> > on older device. Why not?
> >> >>
> >> >Because sometimes switchdev_inactive is needed and sometimes not.
> >> >Such knob is not device decision.
> >>
> >> That is what I would call corner case. In that, user can use userspace
> >> configuration to change the mode in runtime.
> >>
> >Corner vs common depends on users one talks to. :)
> >If fw has switchdev(active) as default, and then
> >And user needs to run switchdev_inactive, it will actually break their switching applications.
> 
> Can you describe the actutal breakage please?
> 
Driver default was switchdev so all the traffic is forwarded to the switch,
and user didn't have chance to setup the fdb rules.
So packets are dropped but user didn't expect the traffic to be forwarded.

With this RFC, the device would start in the switchdev_inactive.
And user's goal is achieved.

> >
> >So, one needs to invent switchdev_inactive in the FW.
> >
> >Jakub's suggestion in this RFC is covering both the scenarios uniformly without above problems.
> >Single uapi for all the cases, so looks good to me.
> >
> >Moreover, do not understand how alternative solves such problems.
> >i.e. user is unable to configure the fw because driver is not yet loaded/up.
> 
> See my other reply in this thread. I don't think there is a need to
> configure anything in FW. If we fix the behaviour in switchdev mode for
> non-sriov user and change the default, no fw knob needed. What am I
> missing?
> 
If I understood your suggestion right, is it the devlinkd based solution?

If yes, then Mark explained that it has the issue of all drivers to be loaded, followed by user space to start.