From: Vladislav Zolotarov Date: Wed, 21 Jul 2010 05:59:01 +0000 (+0000) Subject: bnx2x: Protect a SM state change X-Git-Tag: v2.6.35~25^2~14 X-Git-Url: http://bbs.cooldavid.org/git/?p=net-next-2.6.git;a=commitdiff_plain;h=a13773a53faa28cf79982601b6fc9ddb0ca45f36 bnx2x: Protect a SM state change Bug fix: Protect the statistics state machine state update with a spinlock. Otherwise there was a race condition that would cause the statistics to stay enabled despite the fact that they were disabled in the LINK_DOWN event handler. Signed-off-by: Vladislav Zolotarov Signed-off-by: Dmitry Kravkov Signed-off-by: Eilon Greenstein Signed-off-by: David S. Miller --- diff --git a/drivers/net/bnx2x.h b/drivers/net/bnx2x.h index 8bd23687c53..bb0872a6331 100644 --- a/drivers/net/bnx2x.h +++ b/drivers/net/bnx2x.h @@ -1062,6 +1062,10 @@ struct bnx2x { /* used to synchronize stats collecting */ int stats_state; + + /* used for synchronization of concurrent threads statistics handling */ + spinlock_t stats_lock; + /* used by dmae command loader */ struct dmae_command stats_dmae; int executer_idx; diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c index 57ff5b3bcce..3dc876ce6e1 100644 --- a/drivers/net/bnx2x_main.c +++ b/drivers/net/bnx2x_main.c @@ -4849,16 +4849,18 @@ static const struct { static void bnx2x_stats_handle(struct bnx2x *bp, enum bnx2x_stats_event event) { - enum bnx2x_stats_state state = bp->stats_state; + enum bnx2x_stats_state state; if (unlikely(bp->panic)) return; - bnx2x_stats_stm[state][event].action(bp); + /* Protect a state change flow */ + spin_lock_bh(&bp->stats_lock); + state = bp->stats_state; bp->stats_state = bnx2x_stats_stm[state][event].next_state; + spin_unlock_bh(&bp->stats_lock); - /* Make sure the state has been "changed" */ - smp_wmb(); + bnx2x_stats_stm[state][event].action(bp); if ((event != STATS_EVENT_UPDATE) || netif_msg_timer(bp)) DP(BNX2X_MSG_STATS, "state %d -> event %d -> state %d\n", @@ -9908,6 +9910,7 @@ static int __devinit bnx2x_init_bp(struct bnx2x *bp) mutex_init(&bp->port.phy_mutex); mutex_init(&bp->fw_mb_mutex); + spin_lock_init(&bp->stats_lock); #ifdef BCM_CNIC mutex_init(&bp->cnic_mutex); #endif