nfp: don't add ring size to index calculations

Adding ring size to index calculation is pointless, since index
will be masked with ring size - 1.

Suggested-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 9312a73..68013d0 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -928,7 +928,7 @@ static void nfp_net_tx_complete(struct nfp_net_tx_ring *tx_ring)
        if (qcp_rd_p == tx_ring->qcp_rd_p)
                return;
 
-       todo = D_IDX(tx_ring, qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p);
+       todo = D_IDX(tx_ring, qcp_rd_p - tx_ring->qcp_rd_p);
 
        while (todo--) {
                idx = D_IDX(tx_ring, tx_ring->rd_p++);
@@ -999,7 +999,7 @@ static bool nfp_net_xdp_complete(struct nfp_net_tx_ring *tx_ring)
        if (qcp_rd_p == tx_ring->qcp_rd_p)
                return true;
 
-       todo = D_IDX(tx_ring, qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p);
+       todo = D_IDX(tx_ring, qcp_rd_p - tx_ring->qcp_rd_p);
 
        done_all = todo <= NFP_NET_XDP_MAX_COMPLETE;
        todo = min(todo, NFP_NET_XDP_MAX_COMPLETE);