[PATCH 3/3] net/nfp: fix wrong increment of free list counter for VNIC

[Chaoyong He <chaoyong.he@corigine.com>]

When using flower firmware application, and the ctrl vNIC receiving a
packet that is larger than the mbuf size, the Rx function will break the
receive loop and sent a free list descriptor with random DMA address.

Fix this by moving the increment of the free list descriptor counter
to after the packet size have been checked and acted on.

Fixes: a36634e87e16 ("net/nfp: add flower ctrl VNIC Rx/Tx")

Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
---
 drivers/net/nfp/flower/nfp_flower_ctrl.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/nfp/flower/nfp_flower_ctrl.c b/drivers/net/nfp/flower/nfp_flower_ctrl.c
index 953ab6e98c..3631e764fe 100644
--- a/drivers/net/nfp/flower/nfp_flower_ctrl.c
+++ b/drivers/net/nfp/flower/nfp_flower_ctrl.c
@@ -74,8 +74,6 @@ nfp_flower_ctrl_vnic_recv(void *rx_queue,
 			break;
 		}
 
-		nb_hold++;
-
 		/*
 		 * Grab the mbuf and refill the descriptor with the
 		 * previously allocated mbuf
@@ -127,6 +125,7 @@ nfp_flower_ctrl_vnic_recv(void *rx_queue,
 		rxds->fld.dd = 0;
 		rxds->fld.dma_addr_hi = (dma_addr >> 32) & 0xff;
 		rxds->fld.dma_addr_lo = dma_addr & 0xffffffff;
+		nb_hold++;
 
 		rxq->rd_p++;
 		if (unlikely(rxq->rd_p == rxq->rx_count)) /* wrapping?*/
-- 
2.29.3