On Mon, Mar 14, 2022 at 19:55, Vladimir Oltean <olteanv@xxxxxxxxx> wrote: > On Mon, Mar 14, 2022 at 06:56:49PM +0200, Vladimir Oltean wrote: >> > diff --git a/net/dsa/port.c b/net/dsa/port.c >> > index 58291df14cdb..1a17a0efa2fa 100644 >> > --- a/net/dsa/port.c >> > +++ b/net/dsa/port.c >> > @@ -240,6 +240,10 @@ static int dsa_port_switchdev_sync_attrs(struct dsa_port *dp, >> > if (err && err != -EOPNOTSUPP) >> > return err; >> > >> > + err = dsa_port_mst_enable(dp, br_mst_enabled(br), extack); >> > + if (err && err != -EOPNOTSUPP) >> > + return err; >> >> Sadly this will break down because we don't have unwinding on error in >> place (sorry). We'd end up with an unoffloaded bridge port with >> partially synced bridge port attributes. Could you please add a patch >> previous to this one that handles this, and unoffloads those on error? > > Actually I would rather rename the entire dsa_port_mst_enable() function > to dsa_port_mst_validate() and move it to the beginning of dsa_port_bridge_join(). > This simplifies the unwinding that needs to take place quite a bit. Well you still need to unwind vlan filtering if setting the ageing time fails, which is the most complicated one, right? Still, I agree that _validate is a better name, and then _bridge_join seems like a more reasonable placement. Should the unwinding patch still be part of this series then? While we're here, I actually made this a hard error in both scenarios (but forgot to update the log - will do that in v4, depending on what we decide here). There's a dilemma: - When reacting to the attribute event, i.e. changing the mode on a member we're apart of, we _can't_ return -EOPNOTSUPP as it will be ignored, which is why dsa_port_mst_validate (nee _enable) returns -EINVAL. - When joining a bridge, we _must_ return -EOPNOTSUPP to trigger the software fallback. Having something like this in dsa_port_bridge_join... err = dsa_port_mst_validate(dp); if (err == -EINVAL) return -EOPNOTSUPP; else if (err) return err; ...works I suppose, but feels somewhat awkwark. Any better ideas?
