From bbc7c01e95ceef4e23e343f8cbb6edca887121a5 Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Thu, 20 Oct 2016 11:45:51 +1100 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ncsi/internal.h | 1 + net/ncsi/ncsi-manage.c | 22 +++++++++++++++++++--- 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/net/ncsi/internal.h b/net/ncsi/internal.h index eac48584cdd1..1308a56f2591 100644 --- a/net/ncsi/internal.h +++ b/net/ncsi/internal.h @@ -265,6 +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-manage.c b/net/ncsi/ncsi-manage.c index 4789f8681695..a3bd5fa8ad09 100644 --- a/net/ncsi/ncsi-manage.c +++ b/net/ncsi/ncsi-manage.c @@ -645,6 +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; @@ -750,12 +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; @@ -773,10 +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. */ @@ -794,6 +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); -- 2.20.1