Re: [PATCH net] bnxt_en: Gate TPH enablement behind BNXT_SUPPORTS_QUEUE_API check

[Thomas Walsh]

On Thu, Aug 20, 2026 at 1:40 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> On Wed, 19 Aug 2026 15:18:49 +0530 Pavan Chebbi wrote:
> > >         /* Enable TPH support as part of IRQ request */
> > > -       rc = pcie_enable_tph(bp->pdev, PCI_TPH_ST_IV_MODE);
> > > -       if (!rc)
> > > -               bp->tph_mode = PCI_TPH_ST_IV_MODE;
> > > +       if (BNXT_SUPPORTS_QUEUE_API(bp)) {
> >
> > IMO we should not gate pcie_enable_tph() on BNXT_SUPPORTS_QUEUE_API,
> > since TPH's initial steering-tag placement is valid on its own and
> > re-steering may never be needed in some cases?
> > So in these cases it simply disables the feature.
>
> Since irqs are requested at open wouldn't this mean that users who
> program affinity (all serious users?) will have the wrong TPH? Which
> is presumably worse than no TPH at all?
>
> IMHO the simplicity and consistency is good. AFAIU queue API is
> supported on fairly old bnxt NICs so the combination of CPU needing
> TPH and NIC design being 15(?) years old is rather unlikely in the
> first place. The real scenario where users may run into no queue API
> support is FW being old, in which case FW should be updated?
>
Thank you both for taking a look, I appreciate it.

In this particular situation, the customer had very recently upgraded their
firmware. "RX queue restart failed: err=-95" messages were still observed.

I should note that this was prior to the addition of bnxt_tph_update().