[PATCH] net/ice: fix support for 3 scheduler levels

[Bruce Richardson]

On Wed, May 21, 2025 at 11:52:21AM +0100, Loftus, Ciara wrote:
> > 
> > When using only 3 scheduler levels, the VSI node needs to be a node
> > further down the scheduler hierarchy, rather than one up it as with all
> > other possible level settings (5-9). Take account of this possibility in
> > the code.
> > 
> > Fixes: 4ace7701eb44 ("net/ice: provide parameter to limit scheduler layers")
> > Cc: stable at dpdk.org
> > 
> > Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> > ---
> >  drivers/net/intel/ice/ice_tm.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> > 
> > diff --git a/drivers/net/intel/ice/ice_tm.c b/drivers/net/intel/ice/ice_tm.c
> > index ff3a6cd77f..f2d8e12181 100644
> > --- a/drivers/net/intel/ice/ice_tm.c
> > +++ b/drivers/net/intel/ice/ice_tm.c
> > @@ -818,6 +818,18 @@ commit_new_hierarchy(struct rte_eth_dev *dev)
> >  	uint8_t qg_lvl = q_lvl - 1;
> > 
> >  	struct ice_sched_node *new_vsi_root = hw->vsi_ctx[pf->main_vsi-
> > >idx]->sched.vsi_node[0];
> > +	/* handle case where VSI node needs to move DOWN the hierarchy */
> > +	while (new_vsi_root->tx_sched_layer < new_root_level) {
> > +		if (new_vsi_root->num_children == 0)
> > +			return -1;
> > +		/* remove all child nodes but the first */
> > +		while (new_vsi_root->num_children > 1)
> > +			free_sched_node_recursive(pi, new_vsi_root,
> > +					new_vsi_root->children[1],
> > +					new_vsi_root->vsi_handle);
> > +		new_vsi_root = new_vsi_root->children[0];
> > +	}
> > +	/* handle case where VSI node needs to move UP the hierarchy */
> >  	while (new_vsi_root->tx_sched_layer > new_root_level)
> >  		new_vsi_root = new_vsi_root->parent;
> 
> Acked-by: Ciara Loftus <ciara.loftus at intel.com>
> 
Applied to dpdk-next-net-intel.

/Bruce