Merge branch 'ncsi-fixes'

Gavin Shan says:

====================
net/ncsi: More bug fixes

This series fixes 2 issues that were found during NCSI's availability
testing on BCM5718 and improves HNCDSC AEN handler:

   * PATCH[1] refactors the code so that minimal code change is put
     to PATCH[2].
   * PATCH[2] fixes the NCSI channel's stale link state before doing
     failover.
   * PATCH[3] chooses the hot channel, which was ever chosen as active
     channel, when the available channels are all in link-down state.
   * PATCH[4] improves Host Network Controller Driver Status Change
     (HNCDSC) AEN handler

Changelog
=========
v2:
   * Merged PATCH[v1 1/2] to PATCH[v2 1].
   * Avoid if/else statements in ncsi_suspend_channel() as Joel suggested.
   * Added comments to explain why we need retrieve last link states in
     ncsi_suspend_channel().
====================

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

3 files changed, 112 insertions, 34 deletions

diff --git a/net/ncsi/internal.h b/net/ncsi/internal.h
index 13290a70fa71..1308a56f2591 100644
--- a/net/ncsi/internal.h
+++ b/net/ncsi/internal.h
@@ -246,6 +246,7 @@ enum {
 	ncsi_dev_state_config_gls,
 	ncsi_dev_state_config_done,
 	ncsi_dev_state_suspend_select	= 0x0401,
+	ncsi_dev_state_suspend_gls,
 	ncsi_dev_state_suspend_dcnt,
 	ncsi_dev_state_suspend_dc,
 	ncsi_dev_state_suspend_deselect,
@@ -264,6 +265,7 @@ struct ncsi_dev_priv {
 #endif
 	unsigned int        package_num;     /* Number of packages         */
 	struct list_head    packages;        /* List of packages           */
+	struct ncsi_channel *hot_channel;    /* Channel was ever active    */
 	struct ncsi_request requests[256];   /* Request table              */
 	unsigned int        request_id;      /* Last used request ID       */
 #define NCSI_REQ_START_IDX	1
diff --git a/net/ncsi/ncsi-aen.c b/net/ncsi/ncsi-aen.c
index b41a6617d498..6898e7229285 100644
--- a/net/ncsi/ncsi-aen.c
+++ b/net/ncsi/ncsi-aen.c
@@ -141,23 +141,35 @@ static int ncsi_aen_handler_hncdsc(struct ncsi_dev_priv *ndp,
 		return -ENODEV;
 
 	/* If the channel is active one, we need reconfigure it */
+	spin_lock_irqsave(&nc->lock, flags);
 	ncm = &nc->modes[NCSI_MODE_LINK];
 	hncdsc = (struct ncsi_aen_hncdsc_pkt *)h;
 	ncm->data[3] = ntohl(hncdsc->status);
 	if (!list_empty(&nc->link) ||
-	    nc->state != NCSI_CHANNEL_ACTIVE ||
-	    (ncm->data[3] & 0x1))
+	    nc->state != NCSI_CHANNEL_ACTIVE) {
+		spin_unlock_irqrestore(&nc->lock, flags);
 		return 0;
+	}
 
-	if (ndp->flags & NCSI_DEV_HWA)
+	spin_unlock_irqrestore(&nc->lock, flags);
+	if (!(ndp->flags & NCSI_DEV_HWA) && !(ncm->data[3] & 0x1))
 		ndp->flags |= NCSI_DEV_RESHUFFLE;
 
 	/* If this channel is the active one and the link doesn't
 	 * work, we have to choose another channel to be active one.
 	 * The logic here is exactly similar to what we do when link
 	 * is down on the active channel.
+	 *
+	 * On the other hand, we need configure it when host driver
+	 * state on the active channel becomes ready.
 	 */
 	ncsi_stop_channel_monitor(nc);
+
+	spin_lock_irqsave(&nc->lock, flags);
+	nc->state = (ncm->data[3] & 0x1) ? NCSI_CHANNEL_INACTIVE :
+					   NCSI_CHANNEL_ACTIVE;
+	spin_unlock_irqrestore(&nc->lock, flags);
+
 	spin_lock_irqsave(&ndp->lock, flags);
 	list_add_tail_rcu(&nc->link, &ndp->channel_queue);
 	spin_unlock_irqrestore(&ndp->lock, flags);
diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index 5e509e547c2d..a3bd5fa8ad09 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -540,42 +540,86 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
 		nd->state = ncsi_dev_state_suspend_select;
 		/* Fall through */
 	case ncsi_dev_state_suspend_select:
-	case ncsi_dev_state_suspend_dcnt:
-	case ncsi_dev_state_suspend_dc:
-	case ncsi_dev_state_suspend_deselect:
 		ndp->pending_req_num = 1;
 
-		np = ndp->active_package;
-		nc = ndp->active_channel;
+		nca.type = NCSI_PKT_CMD_SP;
 		nca.package = np->id;
-		if (nd->state == ncsi_dev_state_suspend_select) {
-			nca.type = NCSI_PKT_CMD_SP;
-			nca.channel = NCSI_RESERVED_CHANNEL;
-			if (ndp->flags & NCSI_DEV_HWA)
-				nca.bytes[0] = 0;
-			else
-				nca.bytes[0] = 1;
+		nca.channel = NCSI_RESERVED_CHANNEL;
+		if (ndp->flags & NCSI_DEV_HWA)
+			nca.bytes[0] = 0;
+		else
+			nca.bytes[0] = 1;
+
+		/* To retrieve the last link states of channels in current
+		 * package when current active channel needs fail over to
+		 * another one. It means we will possibly select another
+		 * channel as next active one. The link states of channels
+		 * are most important factor of the selection. So we need
+		 * accurate link states. Unfortunately, the link states on
+		 * inactive channels can't be updated with LSC AEN in time.
+		 */
+		if (ndp->flags & NCSI_DEV_RESHUFFLE)
+			nd->state = ncsi_dev_state_suspend_gls;
+		else
 			nd->state = ncsi_dev_state_suspend_dcnt;
-		} else if (nd->state == ncsi_dev_state_suspend_dcnt) {
-			nca.type = NCSI_PKT_CMD_DCNT;
-			nca.channel = nc->id;
-			nd->state = ncsi_dev_state_suspend_dc;
-		} else if (nd->state == ncsi_dev_state_suspend_dc) {
-			nca.type = NCSI_PKT_CMD_DC;
+		ret = ncsi_xmit_cmd(&nca);
+		if (ret)
+			goto error;
+
+		break;
+	case ncsi_dev_state_suspend_gls:
+		ndp->pending_req_num = np->channel_num;
+
+		nca.type = NCSI_PKT_CMD_GLS;
+		nca.package = np->id;
+
+		nd->state = ncsi_dev_state_suspend_dcnt;
+		NCSI_FOR_EACH_CHANNEL(np, nc) {
 			nca.channel = nc->id;
-			nca.bytes[0] = 1;
-			nd->state = ncsi_dev_state_suspend_deselect;
-		} else if (nd->state == ncsi_dev_state_suspend_deselect) {
-			nca.type = NCSI_PKT_CMD_DP;
-			nca.channel = NCSI_RESERVED_CHANNEL;
-			nd->state = ncsi_dev_state_suspend_done;
+			ret = ncsi_xmit_cmd(&nca);
+			if (ret)
+				goto error;
 		}
 
+		break;
+	case ncsi_dev_state_suspend_dcnt:
+		ndp->pending_req_num = 1;
+
+		nca.type = NCSI_PKT_CMD_DCNT;
+		nca.package = np->id;
+		nca.channel = nc->id;
+
+		nd->state = ncsi_dev_state_suspend_dc;
 		ret = ncsi_xmit_cmd(&nca);
-		if (ret) {
-			nd->state = ncsi_dev_state_functional;
-			return;
-		}
+		if (ret)
+			goto error;
+
+		break;
+	case ncsi_dev_state_suspend_dc:
+		ndp->pending_req_num = 1;
+
+		nca.type = NCSI_PKT_CMD_DC;
+		nca.package = np->id;
+		nca.channel = nc->id;
+		nca.bytes[0] = 1;
+
+		nd->state = ncsi_dev_state_suspend_deselect;
+		ret = ncsi_xmit_cmd(&nca);
+		if (ret)
+			goto error;
+
+		break;
+	case ncsi_dev_state_suspend_deselect:
+		ndp->pending_req_num = 1;
+
+		nca.type = NCSI_PKT_CMD_DP;
+		nca.package = np->id;
+		nca.channel = NCSI_RESERVED_CHANNEL;
+
+		nd->state = ncsi_dev_state_suspend_done;
+		ret = ncsi_xmit_cmd(&nca);
+		if (ret)
+			goto error;
 
 		break;
 	case ncsi_dev_state_suspend_done:
@@ -589,6 +633,10 @@ static void ncsi_suspend_channel(struct ncsi_dev_priv *ndp)
 		netdev_warn(nd->dev, "Wrong NCSI state 0x%x in suspend\n",
 			    nd->state);
 	}
+
+	return;
+error:
+	nd->state = ncsi_dev_state_functional;
 }
 
 static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
@@ -597,6 +645,7 @@ static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
 	struct net_device *dev = nd->dev;
 	struct ncsi_package *np = ndp->active_package;
 	struct ncsi_channel *nc = ndp->active_channel;
+	struct ncsi_channel *hot_nc = NULL;
 	struct ncsi_cmd_arg nca;
 	unsigned char index;
 	unsigned long flags;
@@ -702,12 +751,20 @@ static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
 		break;
 	case ncsi_dev_state_config_done:
 		spin_lock_irqsave(&nc->lock, flags);
-		if (nc->modes[NCSI_MODE_LINK].data[2] & 0x1)
+		if (nc->modes[NCSI_MODE_LINK].data[2] & 0x1) {
+			hot_nc = nc;
 			nc->state = NCSI_CHANNEL_ACTIVE;
-		else
+		} else {
+			hot_nc = NULL;
 			nc->state = NCSI_CHANNEL_INACTIVE;
+		}
 		spin_unlock_irqrestore(&nc->lock, flags);
 
+		/* Update the hot channel */
+		spin_lock_irqsave(&ndp->lock, flags);
+		ndp->hot_channel = hot_nc;
+		spin_unlock_irqrestore(&ndp->lock, flags);
+
 		ncsi_start_channel_monitor(nc);
 		ncsi_process_next_channel(ndp);
 		break;
@@ -725,10 +782,14 @@ error:
 static int ncsi_choose_active_channel(struct ncsi_dev_priv *ndp)
 {
 	struct ncsi_package *np;
-	struct ncsi_channel *nc, *found;
+	struct ncsi_channel *nc, *found, *hot_nc;
 	struct ncsi_channel_mode *ncm;
 	unsigned long flags;
 
+	spin_lock_irqsave(&ndp->lock, flags);
+	hot_nc = ndp->hot_channel;
+	spin_unlock_irqrestore(&ndp->lock, flags);
+
 	/* The search is done once an inactive channel with up
 	 * link is found.
 	 */
@@ -746,6 +807,9 @@ static int ncsi_choose_active_channel(struct ncsi_dev_priv *ndp)
 			if (!found)
 				found = nc;
 
+			if (nc == hot_nc)
+				found = nc;
+
 			ncm = &nc->modes[NCSI_MODE_LINK];
 			if (ncm->data[2] & 0x1) {
 				spin_unlock_irqrestore(&nc->lock, flags);