[PATCH v2] net/nfp: fix bug of disable VLAN strip

[Peng Zhang]

"vlan set strip off 0" can't work, due to the incorrect usage
of the mask, it just represent that the status is changed or not,
not represent offloaded or not, so that the driver send the
error control message to the nic.

Now, by first inspect the mask of things that changed, and then
change the requested state if VLAN stripping according the
requested offload status. So this change can fix this bug.

Fixes: d4a27a3b092a ("nfp: add basic features")
Cc: stable at dpdk.org

Signed-off-by: Peng Zhang <peng.zhang at corigine.com>
Signed-off-by: Yong Xu <yong.xu at corigine.com>
Signed-off-by: Chaoyong He <chaoyong.he at corigine.com>
Signed-off-by: Niklas Söderlund <niklas.soderlund at corigine.com>
---
 drivers/net/nfp/nfp_common.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/net/nfp/nfp_common.c b/drivers/net/nfp/nfp_common.c
index b26770dbfb..57c50ec475 100644
--- a/drivers/net/nfp/nfp_common.c
+++ b/drivers/net/nfp/nfp_common.c
@@ -965,22 +965,25 @@ nfp_net_vlan_offload_set(struct rte_eth_dev *dev, int mask)
 {
 	uint32_t new_ctrl, update;
 	struct nfp_net_hw *hw;
+	struct rte_eth_conf *dev_conf;
 	int ret;
 
 	hw = NFP_NET_DEV_PRIVATE_TO_HW(dev->data->dev_private);
-	new_ctrl = 0;
-
-	/* Enable vlan strip if it is not configured yet */
-	if ((mask & RTE_ETH_VLAN_STRIP_OFFLOAD) &&
-	    !(hw->ctrl & NFP_NET_CFG_CTRL_RXVLAN))
-		new_ctrl = hw->ctrl | NFP_NET_CFG_CTRL_RXVLAN;
+	dev_conf = &dev->data->dev_conf;
+	new_ctrl = hw->ctrl;
 
-	/* Disable vlan strip just if it is configured */
-	if (!(mask & RTE_ETH_VLAN_STRIP_OFFLOAD) &&
-	    (hw->ctrl & NFP_NET_CFG_CTRL_RXVLAN))
-		new_ctrl = hw->ctrl & ~NFP_NET_CFG_CTRL_RXVLAN;
+	/*
+	 * Vlan stripping setting
+	 * Enable or disable VLAN stripping
+	 */
+	if (mask & RTE_ETH_VLAN_STRIP_MASK) {
+		if (dev_conf->rxmode.offloads & RTE_ETH_RX_OFFLOAD_VLAN_STRIP)
+			new_ctrl |= NFP_NET_CFG_CTRL_RXVLAN;
+		else
+			new_ctrl &= ~NFP_NET_CFG_CTRL_RXVLAN;
+	}
 
-	if (new_ctrl == 0)
+	if (new_ctrl == hw->ctrl)
 		return 0;
 
 	update = NFP_NET_CFG_UPDATE_GEN;
-- 
2.27.0