[Intel-wired-lan] [PATCH iwl-next 2/2] ixgbe: add link_down_events statistic

[Martyna Szapar-Mudlaw]

Introduce a new ethtool statistic to ixgbe driver, `link_down_events`,
to track the number of times the link transitions from up to down.
This counter can help diagnose issues related to link stability,
such as port flapping or unexpected link drops.

The counter increments when a link-down event occurs and is exposed
via ethtool stats as `link_down_events`.

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov at intel.com>
Signed-off-by: Martyna Szapar-Mudlaw <martyna.szapar-mudlaw at linux.intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe.h         | 1 +
 drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c | 1 +
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c    | 2 ++
 3 files changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index e6a380d4929b..7a8b4b6053c7 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -743,6 +743,7 @@ struct ixgbe_adapter {
 	bool link_up;
 	unsigned long sfp_poll_time;
 	unsigned long link_check_timeout;
+	u32 link_down_events;
 
 	struct timer_list service_timer;
 	struct work_struct service_task;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
index f03925c1f521..ea1d2c2390f1 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
@@ -91,6 +91,7 @@ static const struct ixgbe_stats ixgbe_gstrings_stats[] = {
 	{"rx_hwtstamp_cleared", IXGBE_STAT(rx_hwtstamp_cleared)},
 	{"tx_ipsec", IXGBE_STAT(tx_ipsec)},
 	{"rx_ipsec", IXGBE_STAT(rx_ipsec)},
+	{"link_down_events", IXGBE_STAT(link_down_events)},
 #ifdef IXGBE_FCOE
 	{"fcoe_bad_fccrc", IXGBE_STAT(stats.fccrc)},
 	{"rx_fcoe_dropped", IXGBE_STAT(stats.fcoerpdc)},
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 467f81239e12..cb5c782817fa 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -7986,6 +7986,8 @@ static void ixgbe_watchdog_link_is_down(struct ixgbe_adapter *adapter)
 	if (!netif_carrier_ok(netdev))
 		return;
 
+	adapter->link_down_events++;
+
 	/* poll for SFP+ cable when link is down */
 	if (ixgbe_is_sfp(hw) && hw->mac.type == ixgbe_mac_82598EB)
 		adapter->flags2 |= IXGBE_FLAG2_SEARCH_FOR_SFP;
-- 
2.47.0