[PATCH v4 4/5] failsafe: use public APIs in fs_link_update

[Luc Pelletier <lucp.at.work@gmail.com>]

The link_update function pointer is called directly on a sub-device, via
its rte_eth_dev structure. In addition, it assumes that if link_update
returns a value other than 0 or -1, an error occurred. That's not
accurate. For example, the mlx5 PMD returns a positive value to indicate
that the link status was updated. This results in fs_link_update failing
when it really should have succeeded.

The code now uses the public APIs rte_eth_link_get and
rte_eth_link_get_nowait to query the link status of each sub-device. It
also uses rte_eth_linkstatus_set to set the link status of the failsafe
device.

Fixes: ae80146c5a1b ("net/failsafe: fix removed device handling")
Cc: Matan Azrad <matan@nvidia.com>
Cc: stable@dpdk.org

Signed-off-by: Luc Pelletier <lucp.at.work@gmail.com>
---
 drivers/net/failsafe/failsafe_ops.c | 37 +++++++++++++----------------
 1 file changed, 17 insertions(+), 20 deletions(-)

diff --git a/drivers/net/failsafe/failsafe_ops.c b/drivers/net/failsafe/failsafe_ops.c
index d357e1bc83..b66dfa269b 100644
--- a/drivers/net/failsafe/failsafe_ops.c
+++ b/drivers/net/failsafe/failsafe_ops.c
@@ -820,34 +820,31 @@ fs_link_update(struct rte_eth_dev *dev,
 {
 	struct sub_device *sdev;
 	uint8_t i;
-	int ret;
+	int ret = -1;
+	int sdev_link_ret;
+	struct rte_eth_link link_info;
 
 	fs_lock(dev, 0);
 	FOREACH_SUBDEV_STATE(sdev, i, dev, DEV_ACTIVE) {
-		DEBUG("Calling link_update on sub_device %d", i);
-		ret = (SUBOPS(sdev, link_update))(ETH(sdev), wait_to_complete);
-		if (ret && ret != -1 && sdev->remove == 0 &&
-		    rte_eth_dev_is_removed(PORT_ID(sdev)) == 0) {
-			ERROR("Link update failed for sub_device %d with error %d",
-			      i, ret);
-			fs_unlock(dev, 0);
-			return ret;
+		DEBUG("Calling rte_eth_link_get on sub_device %d", i);
+		if (wait_to_complete) {
+			sdev_link_ret = rte_eth_link_get(PORT_ID(sdev), &link_info);
+		} else {
+			sdev_link_ret = rte_eth_link_get_nowait(PORT_ID(sdev),
+				&link_info);
 		}
-	}
-	if (TX_SUBDEV(dev)) {
-		struct rte_eth_link *l1;
-		struct rte_eth_link *l2;
 
-		l1 = &dev->data->dev_link;
-		l2 = &ETH(TX_SUBDEV(dev))->data->dev_link;
-		if (memcmp(l1, l2, sizeof(*l1))) {
-			*l1 = *l2;
-			fs_unlock(dev, 0);
-			return 0;
+		if (likely(sdev_link_ret == 0)) {
+			if (TX_SUBDEV(dev) == sdev)
+				ret = rte_eth_linkstatus_set(dev, &link_info);
+		} else if (sdev->remove == 0 &&
+				rte_eth_dev_is_removed(PORT_ID(sdev)) == 0) {
+			ERROR("Link get failed for sub_device %d with error %d",
+				i, sdev_link_ret);
 		}
 	}
 	fs_unlock(dev, 0);
-	return -1;
+	return ret;
 }
 
 static int
-- 
2.38.1