net/ncsi: Choose hot channel as active one if necessary
The issue was found on BCM5718 which has two NCSI channels in one
package: C0 and C1. C0 is in link-up state while C1 is in link-down
state. C0 is chosen as active channel until unplugging and plugging
C0's cable: On unplugging C0's cable, LSC (Link State Change) AEN
packet received on C0 to report link-down event. After that, C1 is
chosen as active channel. LSC AEN for link-up event is lost on C0
when plugging C0's cable back. We lose the network even C0 is usable.
This resolves the issue by recording the (hot) channel that was ever
chosen as active one. The hot channel is chosen to be active one
if none of available channels in link-up state. With this, C0 is still
the active one after unplugging C0's cable. LSC AEN packet received
on C0 when plugging its cable back.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index 4789f86..a3bd5fa 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -645,6 +645,7 @@
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;
@@ -750,12 +751,20 @@
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;
@@ -773,10 +782,14 @@
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.
*/
@@ -794,6 +807,9 @@
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);