Re: [PATCH net-next 2/5] bnxt_en: Resize RSS contexts on channel count change

[Björn Töpel]

On Wed, 4 Mar 2026 at 01:05, Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> On Tue,  3 Mar 2026 19:15:30 +0100 Björn Töpel wrote:
> > -     if (bnxt_get_nr_rss_ctxs(bp, req_rx_rings) !=
> > -         bnxt_get_nr_rss_ctxs(bp, bp->rx_nr_rings) &&
> > -         netif_is_rxfh_configured(dev)) {
> > -             netdev_warn(dev, "RSS table size change required, RSS table entries must be default to proceed\n");
> > -             return -EINVAL;
> > +     if (bnxt_get_nr_rss_ctxs(bp, req_rx_rings) != bnxt_get_nr_rss_ctxs(bp, bp->rx_nr_rings)) {
> > +             u32 new_size = bnxt_get_nr_rss_ctxs(bp, req_rx_rings) * BNXT_RSS_TABLE_ENTRIES_P5;
> > +             u32 old_size = bnxt_get_rxfh_indir_size(dev);
> > +
> > +             /* Validate context 0 can be resized before mutating anything */
> > +             if (netif_is_rxfh_configured(dev) &&
> > +                 ethtool_rxfh_indir_can_resize(bp->rss_indir_tbl, old_size, new_size)) {
> > +                     netdev_warn(dev, "RSS table size change not supported with current indirection table\n");
> > +                     return -EINVAL;
> > +             }
> > +
> > +             rc = ethtool_rxfh_contexts_resize_all(dev, new_size);
> > +             if (rc)
> > +                     return rc;
> > +
> > +             /* All validated; apply context 0 resize */
> > +             if (netif_is_rxfh_configured(dev))
> > +                     ethtool_rxfh_indir_resize(bp->rss_indir_tbl, old_size, new_size);
> >       }
> >
> >       rc = bnxt_check_rings(bp, req_tx_rings, req_rx_rings, sh, tcs, tx_xdp);
>
> You resize the tables even if something else fails later on.
> I think either this if () should only contain the validation checks,
> and the actual resizing has to happen later.
> Or you need to "un-resize" (which should never fail so it's fine).

Good point!