Querying link parameters in mlx5 driver is implemented using
either ETHTOOL_GLINKSETTINGS or ETHTOOL_GSET ioctl commands.
Link status reported by the above can be stale, due to a delay
introduced by Linux kernel's linkwatch mechanism.
This patch fixes that by reading link carrier status through
ETHTOOL_GLINK command. This ethtool command,
implemented by mlx5 since kernel 4.14, will always get
the current link status. It also flushes the pending link watch
events, so following ETHTOOL_GLINKSETTINGS/ETHTOOL_GSET will
return actual link carrier status.
Fixes: 17f95513adca ("net/mlx5: fix link status change detection")
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Cosmin Ratiu <[email protected]>
Signed-off-by: Dariusz Sosnowski <[email protected]>
---
.mailmap | 1 +
drivers/net/mlx5/linux/mlx5_ethdev_os.c | 46 ++++++++++++++++++++++---
drivers/net/mlx5/mlx5.h | 1 +
3 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/.mailmap b/.mailmap
index c350b8f2b5..1723ef8fa7 100644
--- a/.mailmap
+++ b/.mailmap
@@ -316,6 +316,7 @@ Congjie Zhou <[email protected]>
Congwen Zhang <[email protected]>
Conor Fogarty <[email protected]>
Conor Walsh <[email protected]>
+Cosmin Ratiu <[email protected]>
Cristian Bidea <[email protected]>
Cristian Dumitrescu <[email protected]>
Cristian Sovaiala <[email protected]>
diff --git a/drivers/net/mlx5/linux/mlx5_ethdev_os.c
b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
index f6394ebd19..f30fb6da5c 100644
--- a/drivers/net/mlx5/linux/mlx5_ethdev_os.c
+++ b/drivers/net/mlx5/linux/mlx5_ethdev_os.c
@@ -317,6 +317,40 @@ mlx5_find_master_dev(struct rte_eth_dev *dev)
return NULL;
}
+/**
+ * Retrieve the carrier state of a device.
+ *
+ * The IFF_RUNNING flag reported by SIOCGIFFLAGS reflects the RFC 2863
+ * operational state, which the kernel only refreshes from its link watch
+ * work queue and which may therefore lag the actual carrier by up to a
+ * second. ETHTOOL_GLINK reports the carrier directly, and additionally
+ * flushes any link watch event still pending for the device.
+ *
+ * @param dev
+ * Pointer to Ethernet device structure.
+ *
+ * @return
+ * 1 if the carrier is up, 0 otherwise.
+ * Negative errno value is returned on error.
+ */
+int
+mlx5_link_carrier_get(struct rte_eth_dev *dev)
+{
+ struct ethtool_value ecmd = {
+ .cmd = ETHTOOL_GLINK,
+ };
+ struct ifreq ifr = {
+ .ifr_data = (void *)&ecmd,
+ };
+ int ret;
+
+ ret = mlx5_ifreq(dev, SIOCETHTOOL, &ifr);
+ if (ret != 0)
+ return ret;
+
+ return !!ecmd.data;
+}
+
/**
* DPDK callback to retrieve physical link information.
*
@@ -347,9 +381,11 @@ mlx5_link_update_unlocked_gset(struct rte_eth_dev *dev,
dev->data->port_id, strerror(rte_errno));
return ret;
}
+ ret = mlx5_link_carrier_get(dev);
+ if (ret < 0)
+ return ret;
dev_link = (struct rte_eth_link) {
- .link_status = ((ifr.ifr_flags & IFF_UP) &&
- (ifr.ifr_flags & IFF_RUNNING)),
+ .link_status = ((ifr.ifr_flags & IFF_UP) && ret),
};
ifr = (struct ifreq) {
.ifr_data = (void *)&edata,
@@ -428,9 +464,11 @@ mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev,
dev->data->port_id, strerror(rte_errno));
return ret;
}
+ ret = mlx5_link_carrier_get(dev);
+ if (ret < 0)
+ return ret;
dev_link = (struct rte_eth_link) {
- .link_status = ((ifr.ifr_flags & IFF_UP) &&
- (ifr.ifr_flags & IFF_RUNNING)),
+ .link_status = ((ifr.ifr_flags & IFF_UP) && ret),
};
ifr = (struct ifreq) {
.ifr_data = (void *)&gcmd,
diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index 7923125c5c..5ea49ca807 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -2391,6 +2391,7 @@ int mlx5_get_mtu(struct rte_eth_dev *dev, uint16_t *mtu);
int mlx5_set_mtu(struct rte_eth_dev *dev, uint16_t mtu);
int mlx5_read_clock(struct rte_eth_dev *dev, uint64_t *clock);
int mlx5_link_update(struct rte_eth_dev *dev, int wait_to_complete);
+int mlx5_link_carrier_get(struct rte_eth_dev *dev);
int mlx5_dev_get_flow_ctrl(struct rte_eth_dev *dev,
struct rte_eth_fc_conf *fc_conf);
int mlx5_dev_set_flow_ctrl(struct rte_eth_dev *dev,
--
2.43.0
