+int nfp_net_set_ring_size(struct nfp_net *nn, u32 rxd_cnt, u32 txd_cnt)
+{
+ struct nfp_net_tx_ring *tx_rings = NULL;
+ struct nfp_net_rx_ring *rx_rings = NULL;
+ u32 old_rxd_cnt, old_txd_cnt;
+ int err;
+
+ if (!netif_running(nn->netdev)) {
+ nn->rxd_cnt = rxd_cnt;
+ nn->txd_cnt = txd_cnt;
+ return 0;
+ }
+
+ old_rxd_cnt = nn->rxd_cnt;
+ old_txd_cnt = nn->txd_cnt;
+
+ /* Prepare new rings */
+ if (nn->rxd_cnt != rxd_cnt) {
+ rx_rings = nfp_net_shadow_rx_rings_prepare(nn, nn->fl_bufsz,
+ rxd_cnt);
+ if (!rx_rings)
+ return -ENOMEM;
+ }
+ if (nn->txd_cnt != txd_cnt) {
+ tx_rings = nfp_net_shadow_tx_rings_prepare(nn, txd_cnt);
+ if (!tx_rings) {
+ nfp_net_shadow_rx_rings_free(nn, rx_rings);
+ return -ENOMEM;
+ }
+ }
+
+ /* Stop device, swap in new rings, try to start the firmware */
+ nfp_net_close_stack(nn);
+ nfp_net_clear_config_and_disable(nn);
+
+ if (rx_rings)
+ rx_rings = nfp_net_shadow_rx_rings_swap(nn, rx_rings);
+ if (tx_rings)
+ tx_rings = nfp_net_shadow_tx_rings_swap(nn, tx_rings);
+
+ nn->rxd_cnt = rxd_cnt;
+ nn->txd_cnt = txd_cnt;
+
+ err = nfp_net_set_config_and_enable(nn);
+ if (err) {
+ const int err_new = err;
+
+ /* Try with old configuration and old rings */
+ if (rx_rings)
+ rx_rings = nfp_net_shadow_rx_rings_swap(nn, rx_rings);
+ if (tx_rings)
+ tx_rings = nfp_net_shadow_tx_rings_swap(nn, tx_rings);
+
+ nn->rxd_cnt = old_rxd_cnt;
+ nn->txd_cnt = old_txd_cnt;
+
+ err = __nfp_net_set_config_and_enable(nn);
+ if (err)
+ nn_err(nn, "Can't restore ring config - FW communication failed (%d,%d)\n",
+ err_new, err);
+ }
+
+ nfp_net_shadow_rx_rings_free(nn, rx_rings);
+ nfp_net_shadow_tx_rings_free(nn, tx_rings);
+
+ nfp_net_open_stack(nn);
+
+ return err;
+}
+