Merge branch 'ncsi-next'

Gavin Shan says:

====================
net/ncsi: NCSI Improvment and bug fixes

This series of patches improves NCSI stack according to the comments
I received after the NCSI code was merged to 4.8.rc1:

  * PATCH[1/8] fixes the build warning caused by xchg() with ia64-linux-gcc.
    The atomic operations are removed. The NCSI's lock should be taken when
    reading or updating its state and chained state.
  * Channel ID (0x1f) is the reserved one and it cannot be valid channel ID.
    So we needn't try to probe channel whose ID is 0x1f. PATCH[2/8] and
    PATCH[3/8] are addressing this issue.
  * The request IDs are assigned in round-robin fashion, but it's broken.
    PATCH[4/8] make it work.
  * PATCH[5/8] and PATCH[6/8] reworks the channel monitoring to improve the
    code readability and its robustness.
  * PATCH[7/8] and PATCH[8/8] introduces ncsi_stop_dev() so that the network
    device can be closed and opened afterwards. No error will be seen.

Changelog
=========
v2:
  * The NCSI's lock is taken when reading or updating its state as the
    {READ,WRITE}_ONCE() isn't reliable.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 180 insertions, 90 deletions

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index 90f9c5481290..262587240c86 100644
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -1190,6 +1190,8 @@ static int ftgmac100_stop(struct net_device *netdev)
 	napi_disable(&priv->napi);
 	if (netdev->phydev)
 		phy_stop(netdev->phydev);
+	else if (priv->use_ncsi)
+		ncsi_stop_dev(priv->ndev);
 
 	ftgmac100_stop_hw(priv);
 	free_irq(priv->irq, netdev);
diff --git a/include/net/ncsi.h b/include/net/ncsi.h
index 1dbf42f79750..68680baac0fd 100644
--- a/include/net/ncsi.h
+++ b/include/net/ncsi.h
@@ -31,6 +31,7 @@ struct ncsi_dev {
 struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
 				   void (*notifier)(struct ncsi_dev *nd));
 int ncsi_start_dev(struct ncsi_dev *nd);
+void ncsi_stop_dev(struct ncsi_dev *nd);
 void ncsi_unregister_dev(struct ncsi_dev *nd);
 #else /* !CONFIG_NET_NCSI */
 static inline struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
@@ -44,6 +45,10 @@ static inline int ncsi_start_dev(struct ncsi_dev *nd)
 	return -ENOTTY;
 }
 
+static void ncsi_stop_dev(struct ncsi_dev *nd)
+{
+}
+
 static inline void ncsi_unregister_dev(struct ncsi_dev *nd)
 {
 }
diff --git a/net/ncsi/internal.h b/net/ncsi/internal.h
index 33738c060547..13290a70fa71 100644
--- a/net/ncsi/internal.h
+++ b/net/ncsi/internal.h
@@ -170,6 +170,7 @@ struct ncsi_package;
 
 #define NCSI_PACKAGE_SHIFT	5
 #define NCSI_PACKAGE_INDEX(c)	(((c) >> NCSI_PACKAGE_SHIFT) & 0x7)
+#define NCSI_RESERVED_CHANNEL	0x1f
 #define NCSI_CHANNEL_INDEX(c)	((c) & ((1 << NCSI_PACKAGE_SHIFT) - 1))
 #define NCSI_TO_CHANNEL(p, c)	(((p) << NCSI_PACKAGE_SHIFT) | (c))
 
@@ -186,9 +187,15 @@ struct ncsi_channel {
 	struct ncsi_channel_mode    modes[NCSI_MODE_MAX];
 	struct ncsi_channel_filter  *filters[NCSI_FILTER_MAX];
 	struct ncsi_channel_stats   stats;
-	struct timer_list           timer;	/* Link monitor timer  */
-	bool                        enabled;	/* Timer is enabled    */
-	unsigned int                timeout;	/* Times of timeout    */
+	struct {
+		struct timer_list   timer;
+		bool                enabled;
+		unsigned int        state;
+#define NCSI_CHANNEL_MONITOR_START	0
+#define NCSI_CHANNEL_MONITOR_RETRY	1
+#define NCSI_CHANNEL_MONITOR_WAIT	2
+#define NCSI_CHANNEL_MONITOR_WAIT_MAX	5
+	} monitor;
 	struct list_head            node;
 	struct list_head            link;
 };
@@ -206,7 +213,8 @@ struct ncsi_package {
 struct ncsi_request {
 	unsigned char        id;      /* Request ID - 0 to 255           */
 	bool                 used;    /* Request that has been assigned  */
-	bool                 driven;  /* Drive state machine             */
+	unsigned int         flags;   /* NCSI request property           */
+#define NCSI_REQ_FLAG_EVENT_DRIVEN	1
 	struct ncsi_dev_priv *ndp;    /* Associated NCSI device          */
 	struct sk_buff       *cmd;    /* Associated NCSI command packet  */
 	struct sk_buff       *rsp;    /* Associated NCSI response packet */
@@ -258,6 +266,7 @@ struct ncsi_dev_priv {
 	struct list_head    packages;        /* List of packages           */
 	struct ncsi_request requests[256];   /* Request table              */
 	unsigned int        request_id;      /* Last used request ID       */
+#define NCSI_REQ_START_IDX	1
 	unsigned int        pending_req_num; /* Number of pending requests */
 	struct ncsi_package *active_package; /* Currently handled package  */
 	struct ncsi_channel *active_channel; /* Currently handled channel  */
@@ -274,7 +283,7 @@ struct ncsi_cmd_arg {
 	unsigned char        package;     /* Destination package ID        */
 	unsigned char        channel;     /* Detination channel ID or 0x1f */
 	unsigned short       payload;     /* Command packet payload length */
-	bool                 driven;      /* Drive the state machine?      */
+	unsigned int         req_flags;   /* NCSI request properties       */
 	union {
 		unsigned char  bytes[16]; /* Command packet specific data  */
 		unsigned short words[8];
@@ -313,7 +322,8 @@ void ncsi_find_package_and_channel(struct ncsi_dev_priv *ndp,
 				   unsigned char id,
 				   struct ncsi_package **np,
 				   struct ncsi_channel **nc);
-struct ncsi_request *ncsi_alloc_request(struct ncsi_dev_priv *ndp, bool driven);
+struct ncsi_request *ncsi_alloc_request(struct ncsi_dev_priv *ndp,
+					unsigned int req_flags);
 void ncsi_free_request(struct ncsi_request *nr);
 struct ncsi_dev *ncsi_find_dev(struct net_device *dev);
 int ncsi_process_next_channel(struct ncsi_dev_priv *ndp);
diff --git a/net/ncsi/ncsi-aen.c b/net/ncsi/ncsi-aen.c
index d463468442ae..b41a6617d498 100644
--- a/net/ncsi/ncsi-aen.c
+++ b/net/ncsi/ncsi-aen.c
@@ -53,7 +53,9 @@ static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
 	struct ncsi_aen_lsc_pkt *lsc;
 	struct ncsi_channel *nc;
 	struct ncsi_channel_mode *ncm;
-	unsigned long old_data;
+	bool chained;
+	int state;
+	unsigned long old_data, data;
 	unsigned long flags;
 
 	/* Find the NCSI channel */
@@ -62,20 +64,27 @@ static int ncsi_aen_handler_lsc(struct ncsi_dev_priv *ndp,
 		return -ENODEV;
 
 	/* Update the link status */
-	ncm = &nc->modes[NCSI_MODE_LINK];
 	lsc = (struct ncsi_aen_lsc_pkt *)h;
+
+	spin_lock_irqsave(&nc->lock, flags);
+	ncm = &nc->modes[NCSI_MODE_LINK];
 	old_data = ncm->data[2];
-	ncm->data[2] = ntohl(lsc->status);
+	data = ntohl(lsc->status);
+	ncm->data[2] = data;
 	ncm->data[4] = ntohl(lsc->oem_status);
-	if (!((old_data ^ ncm->data[2]) & 0x1) ||
-	    !list_empty(&nc->link))
+
+	chained = !list_empty(&nc->link);
+	state = nc->state;
+	spin_unlock_irqrestore(&nc->lock, flags);
+
+	if (!((old_data ^ data) & 0x1) || chained)
 		return 0;
-	if (!(nc->state == NCSI_CHANNEL_INACTIVE && (ncm->data[2] & 0x1)) &&
-	    !(nc->state == NCSI_CHANNEL_ACTIVE && !(ncm->data[2] & 0x1)))
+	if (!(state == NCSI_CHANNEL_INACTIVE && (data & 0x1)) &&
+	    !(state == NCSI_CHANNEL_ACTIVE && !(data & 0x1)))
 		return 0;
 
 	if (!(ndp->flags & NCSI_DEV_HWA) &&
-	    nc->state == NCSI_CHANNEL_ACTIVE)
+	    state == NCSI_CHANNEL_ACTIVE)
 		ndp->flags |= NCSI_DEV_RESHUFFLE;
 
 	ncsi_stop_channel_monitor(nc);
@@ -97,13 +106,21 @@ static int ncsi_aen_handler_cr(struct ncsi_dev_priv *ndp,
 	if (!nc)
 		return -ENODEV;
 
+	spin_lock_irqsave(&nc->lock, flags);
 	if (!list_empty(&nc->link) ||
-	    nc->state != NCSI_CHANNEL_ACTIVE)
+	    nc->state != NCSI_CHANNEL_ACTIVE) {
+		spin_unlock_irqrestore(&nc->lock, flags);
 		return 0;
+	}
+	spin_unlock_irqrestore(&nc->lock, flags);
 
 	ncsi_stop_channel_monitor(nc);
+	spin_lock_irqsave(&nc->lock, flags);
+	nc->state = NCSI_CHANNEL_INVISIBLE;
+	spin_unlock_irqrestore(&nc->lock, flags);
+
 	spin_lock_irqsave(&ndp->lock, flags);
-	xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+	nc->state = NCSI_CHANNEL_INACTIVE;
 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
 	spin_unlock_irqrestore(&ndp->lock, flags);
 
diff --git a/net/ncsi/ncsi-cmd.c b/net/ncsi/ncsi-cmd.c
index 21057a8ceeac..db7083bfd476 100644
--- a/net/ncsi/ncsi-cmd.c
+++ b/net/ncsi/ncsi-cmd.c
@@ -272,7 +272,7 @@ static struct ncsi_request *ncsi_alloc_command(struct ncsi_cmd_arg *nca)
 	struct sk_buff *skb;
 	struct ncsi_request *nr;
 
-	nr = ncsi_alloc_request(ndp, nca->driven);
+	nr = ncsi_alloc_request(ndp, nca->req_flags);
 	if (!nr)
 		return NULL;
 
diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index ef017b871857..5e509e547c2d 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -132,6 +132,7 @@ static void ncsi_report_link(struct ncsi_dev_priv *ndp, bool force_down)
 	struct ncsi_dev *nd = &ndp->ndev;
 	struct ncsi_package *np;
 	struct ncsi_channel *nc;
+	unsigned long flags;
 
 	nd->state = ncsi_dev_state_functional;
 	if (force_down) {
@@ -142,14 +143,21 @@ static void ncsi_report_link(struct ncsi_dev_priv *ndp, bool force_down)
 	nd->link_up = 0;
 	NCSI_FOR_EACH_PACKAGE(ndp, np) {
 		NCSI_FOR_EACH_CHANNEL(np, nc) {
+			spin_lock_irqsave(&nc->lock, flags);
+
 			if (!list_empty(&nc->link) ||
-			    nc->state != NCSI_CHANNEL_ACTIVE)
+			    nc->state != NCSI_CHANNEL_ACTIVE) {
+				spin_unlock_irqrestore(&nc->lock, flags);
 				continue;
+			}
 
 			if (nc->modes[NCSI_MODE_LINK].data[2] & 0x1) {
+				spin_unlock_irqrestore(&nc->lock, flags);
 				nd->link_up = 1;
 				goto report;
 			}
+
+			spin_unlock_irqrestore(&nc->lock, flags);
 		}
 	}
 
@@ -163,43 +171,55 @@ static void ncsi_channel_monitor(unsigned long data)
 	struct ncsi_package *np = nc->package;
 	struct ncsi_dev_priv *ndp = np->ndp;
 	struct ncsi_cmd_arg nca;
-	bool enabled;
-	unsigned int timeout;
+	bool enabled, chained;
+	unsigned int monitor_state;
 	unsigned long flags;
-	int ret;
+	int state, ret;
 
 	spin_lock_irqsave(&nc->lock, flags);
-	timeout = nc->timeout;
-	enabled = nc->enabled;
+	state = nc->state;
+	chained = !list_empty(&nc->link);
+	enabled = nc->monitor.enabled;
+	monitor_state = nc->monitor.state;
 	spin_unlock_irqrestore(&nc->lock, flags);
 
-	if (!enabled || !list_empty(&nc->link))
+	if (!enabled || chained)
 		return;
-	if (nc->state != NCSI_CHANNEL_INACTIVE &&
-	    nc->state != NCSI_CHANNEL_ACTIVE)
+	if (state != NCSI_CHANNEL_INACTIVE &&
+	    state != NCSI_CHANNEL_ACTIVE)
 		return;
 
-	if (!(timeout % 2)) {
+	switch (monitor_state) {
+	case NCSI_CHANNEL_MONITOR_START:
+	case NCSI_CHANNEL_MONITOR_RETRY:
 		nca.ndp = ndp;
 		nca.package = np->id;
 		nca.channel = nc->id;
 		nca.type = NCSI_PKT_CMD_GLS;
-		nca.driven = false;
+		nca.req_flags = 0;
 		ret = ncsi_xmit_cmd(&nca);
 		if (ret) {
 			netdev_err(ndp->ndev.dev, "Error %d sending GLS\n",
 				   ret);
 			return;
 		}
-	}
 
-	if (timeout + 1 >= 3) {
+		break;
+	case NCSI_CHANNEL_MONITOR_WAIT ... NCSI_CHANNEL_MONITOR_WAIT_MAX:
+		break;
+	default:
 		if (!(ndp->flags & NCSI_DEV_HWA) &&
-		    nc->state == NCSI_CHANNEL_ACTIVE)
+		    state == NCSI_CHANNEL_ACTIVE) {
 			ncsi_report_link(ndp, true);
+			ndp->flags |= NCSI_DEV_RESHUFFLE;
+		}
+
+		spin_lock_irqsave(&nc->lock, flags);
+		nc->state = NCSI_CHANNEL_INVISIBLE;
+		spin_unlock_irqrestore(&nc->lock, flags);
 
 		spin_lock_irqsave(&ndp->lock, flags);
-		xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+		nc->state = NCSI_CHANNEL_INACTIVE;
 		list_add_tail_rcu(&nc->link, &ndp->channel_queue);
 		spin_unlock_irqrestore(&ndp->lock, flags);
 		ncsi_process_next_channel(ndp);
@@ -207,10 +227,9 @@ static void ncsi_channel_monitor(unsigned long data)
 	}
 
 	spin_lock_irqsave(&nc->lock, flags);
-	nc->timeout = timeout + 1;
-	nc->enabled = true;
+	nc->monitor.state++;
 	spin_unlock_irqrestore(&nc->lock, flags);
-	mod_timer(&nc->timer, jiffies + HZ * (1 << (nc->timeout / 2)));
+	mod_timer(&nc->monitor.timer, jiffies + HZ);
 }
 
 void ncsi_start_channel_monitor(struct ncsi_channel *nc)
@@ -218,12 +237,12 @@ void ncsi_start_channel_monitor(struct ncsi_channel *nc)
 	unsigned long flags;
 
 	spin_lock_irqsave(&nc->lock, flags);
-	WARN_ON_ONCE(nc->enabled);
-	nc->timeout = 0;
-	nc->enabled = true;
+	WARN_ON_ONCE(nc->monitor.enabled);
+	nc->monitor.enabled = true;
+	nc->monitor.state = NCSI_CHANNEL_MONITOR_START;
 	spin_unlock_irqrestore(&nc->lock, flags);
 
-	mod_timer(&nc->timer, jiffies + HZ * (1 << (nc->timeout / 2)));
+	mod_timer(&nc->monitor.timer, jiffies + HZ);
 }
 
 void ncsi_stop_channel_monitor(struct ncsi_channel *nc)
@@ -231,14 +250,14 @@ void ncsi_stop_channel_monitor(struct ncsi_channel *nc)
 	unsigned long flags;
 
 	spin_lock_irqsave(&nc->lock, flags);
-	if (!nc->enabled) {
+	if (!nc->monitor.enabled) {
 		spin_unlock_irqrestore(&nc->lock, flags);
 		return;
 	}
-	nc->enabled = false;
+	nc->monitor.enabled = false;
 	spin_unlock_irqrestore(&nc->lock, flags);
 
-	del_timer_sync(&nc->timer);
+	del_timer_sync(&nc->monitor.timer);
 }
 
 struct ncsi_channel *ncsi_find_channel(struct ncsi_package *np,
@@ -267,8 +286,9 @@ struct ncsi_channel *ncsi_add_channel(struct ncsi_package *np, unsigned char id)
 	nc->id = id;
 	nc->package = np;
 	nc->state = NCSI_CHANNEL_INACTIVE;
-	nc->enabled = false;
-	setup_timer(&nc->timer, ncsi_channel_monitor, (unsigned long)nc);
+	nc->monitor.enabled = false;
+	setup_timer(&nc->monitor.timer,
+		    ncsi_channel_monitor, (unsigned long)nc);
 	spin_lock_init(&nc->lock);
 	INIT_LIST_HEAD(&nc->link);
 	for (index = 0; index < NCSI_CAP_MAX; index++)
@@ -405,7 +425,8 @@ void ncsi_find_package_and_channel(struct ncsi_dev_priv *ndp,
  * be same. Otherwise, the bogus response might be replied. So
  * the available IDs are allocated in round-robin fashion.
  */
-struct ncsi_request *ncsi_alloc_request(struct ncsi_dev_priv *ndp, bool driven)
+struct ncsi_request *ncsi_alloc_request(struct ncsi_dev_priv *ndp,
+					unsigned int req_flags)
 {
 	struct ncsi_request *nr = NULL;
 	int i, limit = ARRAY_SIZE(ndp->requests);
@@ -413,30 +434,31 @@ struct ncsi_request *ncsi_alloc_request(struct ncsi_dev_priv *ndp, bool driven)
 
 	/* Check if there is one available request until the ceiling */
 	spin_lock_irqsave(&ndp->lock, flags);
-	for (i = ndp->request_id; !nr && i < limit; i++) {
+	for (i = ndp->request_id; i < limit; i++) {
 		if (ndp->requests[i].used)
 			continue;
 
 		nr = &ndp->requests[i];
 		nr->used = true;
-		nr->driven = driven;
-		if (++ndp->request_id >= limit)
-			ndp->request_id = 0;
+		nr->flags = req_flags;
+		ndp->request_id = i + 1;
+		goto found;
 	}
 
 	/* Fail back to check from the starting cursor */
-	for (i = 0; !nr && i < ndp->request_id; i++) {
+	for (i = NCSI_REQ_START_IDX; i < ndp->request_id; i++) {
 		if (ndp->requests[i].used)
 			continue;
 
 		nr = &ndp->requests[i];
 		nr->used = true;
-		nr->driven = driven;
-		if (++ndp->request_id >= limit)
-			ndp->request_id = 0;
+		nr->flags = req_flags;
+		ndp->request_id = i + 1;
+		goto found;
 	}
-	spin_unlock_irqrestore(&ndp->lock, flags);
 
+found:
+	spin_unlock_irqrestore(&ndp->lock, flags);
 	return nr;
 }
 
@@ -458,7 +480,7 @@ void ncsi_free_request(struct ncsi_request *nr)
 	nr->cmd = NULL;
 	nr->rsp = NULL;
 	nr->used = false;
-	driven = nr->driven;
+	driven = !!(nr->flags & NCSI_REQ_FLAG_EVENT_DRIVEN);
 	spin_unlock_irqrestore(&ndp->lock, flags);
 
 	if (driven && cmd && --ndp->pending_req_num == 0)
@@ -508,10 +530,11 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
 	struct ncsi_package *np = ndp->active_package;
 	struct ncsi_channel *nc = ndp->active_channel;
 	struct ncsi_cmd_arg nca;
+	unsigned long flags;
 	int ret;
 
 	nca.ndp = ndp;
-	nca.driven = true;
+	nca.req_flags = NCSI_REQ_FLAG_EVENT_DRIVEN;
 	switch (nd->state) {
 	case ncsi_dev_state_suspend:
 		nd->state = ncsi_dev_state_suspend_select;
@@ -527,7 +550,7 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
 		nca.package = np->id;
 		if (nd->state == ncsi_dev_state_suspend_select) {
 			nca.type = NCSI_PKT_CMD_SP;
-			nca.channel = 0x1f;
+			nca.channel = NCSI_RESERVED_CHANNEL;
 			if (ndp->flags & NCSI_DEV_HWA)
 				nca.bytes[0] = 0;
 			else
@@ -544,7 +567,7 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
 			nd->state = ncsi_dev_state_suspend_deselect;
 		} else if (nd->state == ncsi_dev_state_suspend_deselect) {
 			nca.type = NCSI_PKT_CMD_DP;
-			nca.channel = 0x1f;
+			nca.channel = NCSI_RESERVED_CHANNEL;
 			nd->state = ncsi_dev_state_suspend_done;
 		}
 
@@ -556,7 +579,9 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
 
 		break;
 	case ncsi_dev_state_suspend_done:
-		xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+		spin_lock_irqsave(&nc->lock, flags);
+		nc->state = NCSI_CHANNEL_INACTIVE;
+		spin_unlock_irqrestore(&nc->lock, flags);
 		ncsi_process_next_channel(ndp);
 
 		break;
@@ -574,10 +599,11 @@ static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
 	struct ncsi_channel *nc = ndp->active_channel;
 	struct ncsi_cmd_arg nca;
 	unsigned char index;
+	unsigned long flags;
 	int ret;
 
 	nca.ndp = ndp;
-	nca.driven = true;
+	nca.req_flags = NCSI_REQ_FLAG_EVENT_DRIVEN;
 	switch (nd->state) {
 	case ncsi_dev_state_config:
 	case ncsi_dev_state_config_sp:
@@ -590,7 +616,7 @@ static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
 		else
 			nca.bytes[0] = 1;
 		nca.package = np->id;
-		nca.channel = 0x1f;
+		nca.channel = NCSI_RESERVED_CHANNEL;
 		ret = ncsi_xmit_cmd(&nca);
 		if (ret)
 			goto error;
@@ -675,10 +701,12 @@ static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
 			goto error;
 		break;
 	case ncsi_dev_state_config_done:
+		spin_lock_irqsave(&nc->lock, flags);
 		if (nc->modes[NCSI_MODE_LINK].data[2] & 0x1)
-			xchg(&nc->state, NCSI_CHANNEL_ACTIVE);
+			nc->state = NCSI_CHANNEL_ACTIVE;
 		else
-			xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
+			nc->state = NCSI_CHANNEL_INACTIVE;
+		spin_unlock_irqrestore(&nc->lock, flags);
 
 		ncsi_start_channel_monitor(nc);
 		ncsi_process_next_channel(ndp);
@@ -707,18 +735,25 @@ static int ncsi_choose_active_channel(struct ncsi_dev_priv *ndp)
 	found = NULL;
 	NCSI_FOR_EACH_PACKAGE(ndp, np) {
 		NCSI_FOR_EACH_CHANNEL(np, nc) {
+			spin_lock_irqsave(&nc->lock, flags);
+
 			if (!list_empty(&nc->link) ||
-			    nc->state != NCSI_CHANNEL_INACTIVE)
+			    nc->state != NCSI_CHANNEL_INACTIVE) {
+				spin_unlock_irqrestore(&nc->lock, flags);
 				continue;
+			}
 
 			if (!found)
 				found = nc;
 
 			ncm = &nc->modes[NCSI_MODE_LINK];
 			if (ncm->data[2] & 0x1) {
+				spin_unlock_irqrestore(&nc->lock, flags);
 				found = nc;
 				goto out;
 			}
+
+			spin_unlock_irqrestore(&nc->lock, flags);
 		}
 	}
 
@@ -797,7 +832,7 @@ static void ncsi_probe_channel(struct ncsi_dev_priv *ndp)
 	int ret;
 
 	nca.ndp = ndp;
-	nca.driven = true;
+	nca.req_flags = NCSI_REQ_FLAG_EVENT_DRIVEN;
 	switch (nd->state) {
 	case ncsi_dev_state_probe:
 		nd->state = ncsi_dev_state_probe_deselect;
@@ -807,7 +842,7 @@ static void ncsi_probe_channel(struct ncsi_dev_priv *ndp)
 
 		/* Deselect all possible packages */
 		nca.type = NCSI_PKT_CMD_DP;
-		nca.channel = 0x1f;
+		nca.channel = NCSI_RESERVED_CHANNEL;
 		for (index = 0; index < 8; index++) {
 			nca.package = index;
 			ret = ncsi_xmit_cmd(&nca);
@@ -823,7 +858,7 @@ static void ncsi_probe_channel(struct ncsi_dev_priv *ndp)
 		/* Select all possible packages */
 		nca.type = NCSI_PKT_CMD_SP;
 		nca.bytes[0] = 1;
-		nca.channel = 0x1f;
+		nca.channel = NCSI_RESERVED_CHANNEL;
 		for (index = 0; index < 8; index++) {
 			nca.package = index;
 			ret = ncsi_xmit_cmd(&nca);
@@ -876,7 +911,7 @@ static void ncsi_probe_channel(struct ncsi_dev_priv *ndp)
 		nca.type = NCSI_PKT_CMD_SP;
 		nca.bytes[0] = 1;
 		nca.package = ndp->active_package->id;
-		nca.channel = 0x1f;
+		nca.channel = NCSI_RESERVED_CHANNEL;
 		ret = ncsi_xmit_cmd(&nca);
 		if (ret)
 			goto error;
@@ -884,12 +919,12 @@ static void ncsi_probe_channel(struct ncsi_dev_priv *ndp)
 		nd->state = ncsi_dev_state_probe_cis;
 		break;
 	case ncsi_dev_state_probe_cis:
-		ndp->pending_req_num = 32;
+		ndp->pending_req_num = NCSI_RESERVED_CHANNEL;
 
 		/* Clear initial state */
 		nca.type = NCSI_PKT_CMD_CIS;
 		nca.package = ndp->active_package->id;
-		for (index = 0; index < 0x20; index++) {
+		for (index = 0; index < NCSI_RESERVED_CHANNEL; index++) {
 			nca.channel = index;
 			ret = ncsi_xmit_cmd(&nca);
 			if (ret)
@@ -933,7 +968,7 @@ static void ncsi_probe_channel(struct ncsi_dev_priv *ndp)
 		/* Deselect the active package */
 		nca.type = NCSI_PKT_CMD_DP;
 		nca.package = ndp->active_package->id;
-		nca.channel = 0x1f;
+		nca.channel = NCSI_RESERVED_CHANNEL;
 		ret = ncsi_xmit_cmd(&nca);
 		if (ret)
 			goto error;
@@ -987,11 +1022,14 @@ int ncsi_process_next_channel(struct ncsi_dev_priv *ndp)
 		goto out;
 	}
 
-	old_state = xchg(&nc->state, NCSI_CHANNEL_INVISIBLE);
 	list_del_init(&nc->link);
-
 	spin_unlock_irqrestore(&ndp->lock, flags);
 
+	spin_lock_irqsave(&nc->lock, flags);
+	old_state = nc->state;
+	nc->state = NCSI_CHANNEL_INVISIBLE;
+	spin_unlock_irqrestore(&nc->lock, flags);
+
 	ndp->active_channel = nc;
 	ndp->active_package = nc->package;
 
@@ -1006,7 +1044,7 @@ int ncsi_process_next_channel(struct ncsi_dev_priv *ndp)
 		break;
 	default:
 		netdev_err(ndp->ndev.dev, "Invalid state 0x%x on %d:%d\n",
-			   nc->state, nc->package->id, nc->id);
+			   old_state, nc->package->id, nc->id);
 		ncsi_report_link(ndp, false);
 		return -EINVAL;
 	}
@@ -1070,7 +1108,7 @@ static int ncsi_inet6addr_event(struct notifier_block *this,
 		return NOTIFY_OK;
 
 	nca.ndp = ndp;
-	nca.driven = false;
+	nca.req_flags = 0;
 	nca.package = np->id;
 	nca.channel = nc->id;
 	nca.dwords[0] = nc->caps[NCSI_CAP_MC].cap;
@@ -1118,7 +1156,7 @@ struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
 	/* Initialize private NCSI device */
 	spin_lock_init(&ndp->lock);
 	INIT_LIST_HEAD(&ndp->packages);
-	ndp->request_id = 0;
+	ndp->request_id = NCSI_REQ_START_IDX;
 	for (i = 0; i < ARRAY_SIZE(ndp->requests); i++) {
 		ndp->requests[i].id = i;
 		ndp->requests[i].ndp = ndp;
@@ -1149,9 +1187,7 @@ EXPORT_SYMBOL_GPL(ncsi_register_dev);
 int ncsi_start_dev(struct ncsi_dev *nd)
 {
 	struct ncsi_dev_priv *ndp = TO_NCSI_DEV_PRIV(nd);
-	struct ncsi_package *np;
-	struct ncsi_channel *nc;
-	int old_state, ret;
+	int ret;
 
 	if (nd->state != ncsi_dev_state_registered &&
 	    nd->state != ncsi_dev_state_functional)
@@ -1163,15 +1199,6 @@ int ncsi_start_dev(struct ncsi_dev *nd)
 		return 0;
 	}
 
-	/* Reset channel's state and start over */
-	NCSI_FOR_EACH_PACKAGE(ndp, np) {
-		NCSI_FOR_EACH_CHANNEL(np, nc) {
-			old_state = xchg(&nc->state, NCSI_CHANNEL_INACTIVE);
-			WARN_ON_ONCE(!list_empty(&nc->link) ||
-				     old_state == NCSI_CHANNEL_INVISIBLE);
-		}
-	}
-
 	if (ndp->flags & NCSI_DEV_HWA)
 		ret = ncsi_enable_hwa(ndp);
 	else
@@ -1181,6 +1208,35 @@ int ncsi_start_dev(struct ncsi_dev *nd)
 }
 EXPORT_SYMBOL_GPL(ncsi_start_dev);
 
+void ncsi_stop_dev(struct ncsi_dev *nd)
+{
+	struct ncsi_dev_priv *ndp = TO_NCSI_DEV_PRIV(nd);
+	struct ncsi_package *np;
+	struct ncsi_channel *nc;
+	bool chained;
+	int old_state;
+	unsigned long flags;
+
+	/* Stop the channel monitor and reset channel's state */
+	NCSI_FOR_EACH_PACKAGE(ndp, np) {
+		NCSI_FOR_EACH_CHANNEL(np, nc) {
+			ncsi_stop_channel_monitor(nc);
+
+			spin_lock_irqsave(&nc->lock, flags);
+			chained = !list_empty(&nc->link);
+			old_state = nc->state;
+			nc->state = NCSI_CHANNEL_INACTIVE;
+			spin_unlock_irqrestore(&nc->lock, flags);
+
+			WARN_ON_ONCE(chained ||
+				     old_state == NCSI_CHANNEL_INVISIBLE);
+		}
+	}
+
+	ncsi_report_link(ndp, true);
+}
+EXPORT_SYMBOL_GPL(ncsi_stop_dev);
+
 void ncsi_unregister_dev(struct ncsi_dev *nd)
 {
 	struct ncsi_dev_priv *ndp = TO_NCSI_DEV_PRIV(nd);
diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c
index af84389a6bf1..087db775b3dc 100644
--- a/net/ncsi/ncsi-rsp.c
+++ b/net/ncsi/ncsi-rsp.c
@@ -317,12 +317,12 @@ static int ncsi_rsp_handler_gls(struct ncsi_request *nr)
 	ncm->data[3] = ntohl(rsp->other);
 	ncm->data[4] = ntohl(rsp->oem_status);
 
-	if (nr->driven)
+	if (nr->flags & NCSI_REQ_FLAG_EVENT_DRIVEN)
 		return 0;
 
 	/* Reset the channel monitor if it has been enabled */
 	spin_lock_irqsave(&nc->lock, flags);
-	nc->timeout = 0;
+	nc->monitor.state = NCSI_CHANNEL_MONITOR_START;
 	spin_unlock_irqrestore(&nc->lock, flags);
 
 	return 0;