Re: [v4,net-next,13/15] net: fec: add fec_alloc_rxq_buffers_pp() to allocate buffers from page pool

Jakub Kicinski
2026-01-27T00:18:32Z

On Mon, 26 Jan 2026 02:37:01 +0000 Wei Fang wrote:
> > > + if (is_run) {
> > > + err = fec_enet_alloc_buffers(ndev);
> > > + if (err) {
> > > + netdev_err(ndev, "Failed to alloc buffers\n");
> > > + goto err_alloc_buffers;
> > > + }
> > > +
> > > + fec_restart(ndev);
> > > + napi_enable(&fep->napi);
> > > + netif_tx_start_all_queues(ndev);
> > > + }
> > > +
> > > + return 0;
> > > +
> > > +err_alloc_buffers:
> > > + if (enable) {
> > > + xsk_pool_dma_unmap(pool, 0);
> > > + rxq->xsk_pool = NULL;
> > > + txq->xsk_pool = NULL;
> > > + }
> > > +
> > > + return err;
> >
> > Similarly, the err_alloc_buffers path cleans up the XSK pool state but
> > does not restore NAPI/TX or restart the device when is_run was true.
> > Does this leave the device in the same non-functional state?
> >
>
> The current driver does not support allocating the buffers first and then
> replacing the old buffers, so calling fec_enet_alloc_buffers() again in the
> err_alloc_buffers path may still fail and potentially make the device
> unusable. I will think about how to change this situation. Thanks.

Yes, a lot of older drivers don't. We make people improve things
whenever they try to add major features 🤷️ BTW I'm quite impressed
that AI pointed this out.