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);