From: Sebastian Siewior Date: Mon, 16 Feb 2009 11:28:15 +0000 (+0000) Subject: net/mv643xx: don't disable the mib timer too early and lock properly X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=57e8f26a10ac4af488292199bb0435555f6723f3;p=openwrt%2Fstaging%2Fblogic.git net/mv643xx: don't disable the mib timer too early and lock properly mib_counters_update() also restarts the timer. So the timer is dequeued, the stats are read and then the timer is enqueued again. This is "okay" unless someone unloads the module. The locking here is also broken: mib_counters_update() grabs just a simple spinlock. The only thing the lock is good for is to protect the timer func against other callers namely mv643xx_eth_stop() && mv643xx_eth_get_ethtool_stats(). That means if the spinlock is taken via the ethtool path and than the timer kicks in then the box will lock up. Signed-off-by: Sebastian Andrzej Siewior Acked-by: Lennert Buytenhek Signed-off-by: David S. Miller --- diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c index b6ab46942b98..13f11f402a99 100644 --- a/drivers/net/mv643xx_eth.c +++ b/drivers/net/mv643xx_eth.c @@ -1175,7 +1175,7 @@ static void mib_counters_update(struct mv643xx_eth_private *mp) { struct mib_counters *p = &mp->mib_counters; - spin_lock(&mp->mib_counters_lock); + spin_lock_bh(&mp->mib_counters_lock); p->good_octets_received += mib_read(mp, 0x00); p->good_octets_received += (u64)mib_read(mp, 0x04) << 32; p->bad_octets_received += mib_read(mp, 0x08); @@ -1208,7 +1208,7 @@ static void mib_counters_update(struct mv643xx_eth_private *mp) p->bad_crc_event += mib_read(mp, 0x74); p->collision += mib_read(mp, 0x78); p->late_collision += mib_read(mp, 0x7c); - spin_unlock(&mp->mib_counters_lock); + spin_unlock_bh(&mp->mib_counters_lock); mod_timer(&mp->mib_counters_timer, jiffies + 30 * HZ); } @@ -2216,8 +2216,6 @@ static int mv643xx_eth_stop(struct net_device *dev) wrlp(mp, INT_MASK, 0x00000000); rdlp(mp, INT_MASK); - del_timer_sync(&mp->mib_counters_timer); - napi_disable(&mp->napi); del_timer_sync(&mp->rx_oom); @@ -2229,6 +2227,7 @@ static int mv643xx_eth_stop(struct net_device *dev) port_reset(mp); mv643xx_eth_get_stats(dev); mib_counters_update(mp); + del_timer_sync(&mp->mib_counters_timer); skb_queue_purge(&mp->rx_recycle);