Replace the busy-wait loop using test_and_set_bit(WX_STATE_RESETTING)
with a proper per-device mutex to serialize reset operations.

The reset flag is reserved for other code paths (like watchdog), which
need tocheck if a reset is in process.

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
---
 drivers/net/ethernet/wangxun/libwx/wx_hw.c       |  1 +
 drivers/net/ethernet/wangxun/libwx/wx_type.h     | 16 +---------------
 .../net/ethernet/wangxun/libwx/wx_vf_common.c    |  6 ++++--
 drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c |  6 +++---
 .../net/ethernet/wangxun/txgbe/txgbe_ethtool.c   |  6 +++---
 drivers/net/ethernet/wangxun/txgbe/txgbe_main.c  | 10 +++-------
 6 files changed, 15 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/wangxun/libwx/wx_hw.c b/drivers/net/ethernet/wangxun/libwx/wx_hw.c
index bee9e245e792..05731a50d85f 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_hw.c
+++ b/drivers/net/ethernet/wangxun/libwx/wx_hw.c
@@ -2513,6 +2513,7 @@ int wx_sw_init(struct wx *wx)
 		return -ENOMEM;
 	}
 
+	mutex_init(&wx->reset_lock);
 	bitmap_zero(wx->state, WX_STATE_NBITS);
 	bitmap_zero(wx->flags, WX_PF_FLAGS_NBITS);
 	wx->misc_irq_domain = false;
diff --git a/drivers/net/ethernet/wangxun/libwx/wx_type.h b/drivers/net/ethernet/wangxun/libwx/wx_type.h
index 29e5c5470c94..0fbdda63b141 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_type.h
+++ b/drivers/net/ethernet/wangxun/libwx/wx_type.h
@@ -1400,6 +1400,7 @@ struct wx {
 
 	struct timer_list service_timer;
 	struct work_struct service_task;
+	struct mutex reset_lock; /* mutex for reset */
 };
 
 #define WX_INTR_ALL (~0ULL)
@@ -1478,21 +1479,6 @@ static inline struct wx *phylink_to_wx(struct phylink_config *config)
 	return container_of(config, struct wx, phylink_config);
 }
 
-static inline int wx_set_state_reset(struct wx *wx)
-{
-	u8 timeout = 50;
-
-	while (test_and_set_bit(WX_STATE_RESETTING, wx->state)) {
-		timeout--;
-		if (!timeout)
-			return -EBUSY;
-
-		usleep_range(1000, 2000);
-	}
-
-	return 0;
-}
-
 static inline unsigned int wx_rx_pg_order(struct wx_ring *ring)
 {
 #if (PAGE_SIZE < 8192)
diff --git a/drivers/net/ethernet/wangxun/libwx/wx_vf_common.c b/drivers/net/ethernet/wangxun/libwx/wx_vf_common.c
index ade2bfe563aa..75a6f0898afe 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_vf_common.c
+++ b/drivers/net/ethernet/wangxun/libwx/wx_vf_common.c
@@ -339,14 +339,16 @@ static void wxvf_down(struct wx *wx)
 
 static void wxvf_reinit_locked(struct wx *wx)
 {
-	while (test_and_set_bit(WX_STATE_RESETTING, wx->state))
-		usleep_range(1000, 2000);
+	mutex_lock(&wx->reset_lock);
+	set_bit(WX_STATE_RESETTING, wx->state);
+
 	wxvf_down(wx);
 	wx_free_irq(wx);
 	wx_configure_vf(wx);
 	wx_request_msix_irqs_vf(wx);
 	wxvf_up_complete(wx);
 	clear_bit(WX_STATE_RESETTING, wx->state);
+	mutex_unlock(&wx->reset_lock);
 }
 
 static void wxvf_reset_subtask(struct wx *wx)
diff --git a/drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c b/drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c
index 2b6356622a13..1b76ad897e97 100644
--- a/drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c
+++ b/drivers/net/ethernet/wangxun/ngbe/ngbe_ethtool.c
@@ -32,9 +32,8 @@ static int ngbe_set_ringparam(struct net_device *netdev,
 	    new_rx_count == wx->rx_ring_count)
 		return 0;
 
-	err = wx_set_state_reset(wx);
-	if (err)
-		return err;
+	mutex_lock(&wx->reset_lock);
+	set_bit(WX_STATE_RESETTING, wx->state);
 
 	if (!netif_running(wx->netdev)) {
 		for (i = 0; i < wx->num_tx_queues; i++)
@@ -65,6 +64,7 @@ static int ngbe_set_ringparam(struct net_device *netdev,
 
 clear_reset:
 	clear_bit(WX_STATE_RESETTING, wx->state);
+	mutex_unlock(&wx->reset_lock);
 	return err;
 }
 
diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_ethtool.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_ethtool.c
index 9157b8275be1..46375799d057 100644
--- a/drivers/net/ethernet/wangxun/txgbe/txgbe_ethtool.c
+++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_ethtool.c
@@ -56,9 +56,8 @@ static int txgbe_set_ringparam(struct net_device *netdev,
 	    new_rx_count == wx->rx_ring_count)
 		return 0;
 
-	err = wx_set_state_reset(wx);
-	if (err)
-		return err;
+	mutex_lock(&wx->reset_lock);
+	set_bit(WX_STATE_RESETTING, wx->state);
 
 	if (!netif_running(wx->netdev)) {
 		for (i = 0; i < wx->num_tx_queues; i++)
@@ -88,6 +87,7 @@ static int txgbe_set_ringparam(struct net_device *netdev,
 
 clear_reset:
 	clear_bit(WX_STATE_RESETTING, wx->state);
+	mutex_unlock(&wx->reset_lock);
 	return err;
 }
 
diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
index 0de051450a82..00726605628b 100644
--- a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
+++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c
@@ -598,20 +598,16 @@ int txgbe_setup_tc(struct net_device *dev, u8 tc)
 
 static void txgbe_reinit_locked(struct wx *wx)
 {
-	int err = 0;
-
 	netif_trans_update(wx->netdev);
 
-	err = wx_set_state_reset(wx);
-	if (err) {
-		wx_err(wx, "wait device reset timeout\n");
-		return;
-	}
+	mutex_lock(&wx->reset_lock);
+	set_bit(WX_STATE_RESETTING, wx->state);
 
 	txgbe_down(wx);
 	txgbe_up(wx);
 
 	clear_bit(WX_STATE_RESETTING, wx->state);
+	mutex_unlock(&wx->reset_lock);
 }
 
 void txgbe_do_reset(struct net_device *netdev)
-- 
2.48.1