Hello Haiyang Zhang,
The patch b1d13f7a3b53: "net: mana: Add page pool for RX buffers"
from Aug 4, 2023 (linux-next), leads to the following Smatch static
checker warning:
drivers/net/ethernet/microsoft/mana/mana_en.c:1651 mana_process_rx_cqe()
error: uninitialized symbol 'old_fp'.
drivers/net/ethernet/microsoft/mana/mana_en.c
1592 static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
1593 struct gdma_comp *cqe)
1594 {
1595 struct mana_rxcomp_oob *oob = (struct mana_rxcomp_oob *)cqe->cqe_data;
1596 struct gdma_context *gc = rxq->gdma_rq->gdma_dev->gdma_context;
1597 struct net_device *ndev = rxq->ndev;
1598 struct mana_recv_buf_oob *rxbuf_oob;
1599 struct mana_port_context *apc;
1600 struct device *dev = gc->dev;
1601 void *old_buf = NULL;
1602 u32 curr, pktlen;
1603 bool old_fp;
1604
1605 apc = netdev_priv(ndev);
1606
1607 switch (oob->cqe_hdr.cqe_type) {
1608 case CQE_RX_OKAY:
1609 break;
1610
1611 case CQE_RX_TRUNCATED:
1612 ++ndev->stats.rx_dropped;
1613 rxbuf_oob = &rxq->rx_oobs[rxq->buf_index];
1614 netdev_warn_once(ndev, "Dropped a truncated packet\n");
1615 goto drop;
1616
1617 case CQE_RX_COALESCED_4:
1618 netdev_err(ndev, "RX coalescing is unsupported\n");
1619 apc->eth_stats.rx_coalesced_err++;
1620 return;
1621
1622 case CQE_RX_OBJECT_FENCE:
1623 complete(&rxq->fence_event);
1624 return;
1625
1626 default:
1627 netdev_err(ndev, "Unknown RX CQE type = %d\n",
1628 oob->cqe_hdr.cqe_type);
1629 apc->eth_stats.rx_cqe_unknown_type++;
1630 return;
1631 }
1632
1633 pktlen = oob->ppi[0].pkt_len;
1634
1635 if (pktlen == 0) {
1636 /* data packets should never have packetlength of zero */
1637 netdev_err(ndev, "RX pkt len=0, rq=%u, cq=%u, rxobj=0x%llx\n",
1638 rxq->gdma_id, cq->gdma_id, rxq->rxobj);
1639 return;
1640 }
1641
1642 curr = rxq->buf_index;
1643 rxbuf_oob = &rxq->rx_oobs[curr];
1644 WARN_ON_ONCE(rxbuf_oob->wqe_inf.wqe_size_in_bu != 1);
1645
1646 mana_refill_rx_oob(dev, rxq, rxbuf_oob, &old_buf, &old_fp);
If mana_get_rxfrag() fails then mana_refill_rx_oob() doesn't set *old_fp.
1647
1648 /* Unsuccessful refill will have old_buf == NULL.
1649 * In this case, mana_rx_skb() will drop the packet.
1650 */
--> 1651 mana_rx_skb(old_buf, old_fp, oob, rxq);
1652
1653 drop:
1654 mana_move_wq_tail(rxq->gdma_rq, rxbuf_oob->wqe_inf.wqe_size_in_bu);
1655
1656 mana_post_pkt_rxq(rxq);
1657 }
regards,
dan carpenter
