net/fm10k: fix mbuf free in vector Rx

[ upstream commit 84fff34 ]

There's a corner case that all the Rx queue mbufs are allocated but none
of them is used, this patch fixes mbuf free for this case.

Fixes: b6719f8 ("fm10k: release mbuf for vector Rx")

Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Signed-off-by: Anna Lukin <annal@silicom.co.il>
Reviewed-by: Xiaolong Ye <xiaolong.ye@intel.com>

drivers/net/fm10k/fm10k_rxtx_vec.c

@@ -359,8 +359,15 @@ fm10k_rx_queue_release_mbufs_vec(struct fm10k_rx_queue *rxq)
 		return;
 
 	/* free all mbufs that are valid in the ring */
-	for (i = rxq->next_dd; i != rxq->rxrearm_start; i = (i + 1) & mask)
-		rte_pktmbuf_free_seg(rxq->sw_ring[i]);
+	if (rxq->rxrearm_nb == 0) {
+		for (i = 0; i < rxq->nb_desc; i++)
+			if (rxq->sw_ring[i] != NULL)
+				rte_pktmbuf_free_seg(rxq->sw_ring[i]);
+	} else {
+		for (i = rxq->next_dd; i != rxq->rxrearm_start;
+				i = (i + 1) & mask)
+			rte_pktmbuf_free_seg(rxq->sw_ring[i]);
+	}
 	rxq->rxrearm_nb = rxq->nb_desc;
 
 	/* set all entries to NULL */