Re: [PATCH net-next] net: dsa: loop: Fix devlink resource ID

From: Andrew Lunn

Date: Wed Jun 10 2026 - 16:29:00 EST


On Wed, Jun 10, 2026 at 09:36:59PM +0800, David Yang wrote:
> On Wed, Jun 10, 2026 at 3:23 PM Andrew Lunn <andrew@xxxxxxx> wrote:
> >
> > On Wed, Jun 10, 2026 at 02:25:45PM +0800, David Yang wrote:
> > > Fix collision with DEVLINK_RESOURCE_ID_PARENT_TOP (0) by keeping the
> > > real resource IDs in enum dsa_loop_devlink_resource_id starting at 1.
> >
> > Please could you expand on this. What is actually wrong here?
> >
> > When i look at mv88e6xxx, hellcreak and b53 it does the same.
> >
> > Andrew
>
> dsa_devlink_resource_register() is, but other users of
> devl_resource_register() (mlxsw and netdevsim) avoid 0 explicitly.
>
> In this case for dsa_loop, the usage is semantically questionable (0
> being its own parent) but might just work as well. But it is a real
> problem on mv88e6xxx, where ATU_bin_* are in fact registered as
> top-level siblings, not as children of ATU, due to ATU ID colliding
> with PARENT_TOP.

So please produce a patchset fixing all users of
devl_resource_register() which pass 0. And then maybe add WARN_ON()?

Andrew

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