Re: [PATCH v3 net-next 09/10] selftests/tc-testing: test that taprio can only be attached as root

From: Vladimir Oltean
Date: Fri Aug 04 2023 - 07:14:52 EST

On Thu, Aug 03, 2023 at 02:21:07PM -0300, Victor Nogueira wrote:
> On 01/08/2023 15:24, Vladimir Oltean wrote:
> > Check that the "Can only be attached as root qdisc" error message from
> > taprio is effective by attempting to attach it to a class of another
> > taprio qdisc. That operation should fail.
> >
> > In the bug that was squashed by change "net/sched: taprio: try again to
> > report q->qdiscs[] to qdisc_leaf()", grafting a child taprio to a root
> > software taprio would be misinterpreted as a change() to the root
> > taprio. Catch this by looking at whether the base-time of the root
> > taprio has changed to follow the base-time of the child taprio,
> > something which should have absolutely never happened assuming correct
> > semantics.
> >
> > Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> > Reviewed-by: Pedro Tammela <pctammela@xxxxxxxxxxxx>
> If I understood correctly, these tests depend on CONFIG_PTP_1588_CLOCK_MOCK.
> If that is the case, you should add it to the tdc
> config file (tools/testing/selftests/tc-testing/config).

Thanks, will do.