From 731c6531684250c46d732e369b25b003356f3947 Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Mon, 30 Mar 2009 15:55:24 +0200 Subject: [PATCH] p54spi: fix locking warning in p54spi_op_tx This patch fixes the following waring: > ------------[ cut here ]------------ >WARNING: at kernel/softirq.c:138 local_bh_enable+0x54/0xbc() >Modules linked in: p54spi >[] (dump_stack+0x0/0x14) >[] (warn_on_slowpath+0x0/0x68) >[] (local_bh_enable+0x0/0xbc) >[] (p54spi_op_tx+0x0/0x4c [p54spi]) >[] (p54_sta_unlock+0x0/0x78) p54spi_op_tx needs to be called from different locking contexts. Therefore we have to protect the linked list with irqsave spinlocks. Reported-by: Max Filippov Signed-off-by: Christian Lamparter Signed-off-by: John W. Linville --- drivers/net/wireless/p54/p54spi.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/net/wireless/p54/p54spi.c b/drivers/net/wireless/p54/p54spi.c index 2b222aa..d1fe577 100644 --- a/drivers/net/wireless/p54/p54spi.c +++ b/drivers/net/wireless/p54/p54spi.c @@ -457,9 +457,10 @@ static int p54spi_wq_tx(struct p54s_priv *priv) struct ieee80211_tx_info *info; struct p54_tx_info *minfo; struct p54s_tx_info *dinfo; + unsigned long flags; int ret = 0; - spin_lock_bh(&priv->tx_lock); + spin_lock_irqsave(&priv->tx_lock, flags); while (!list_empty(&priv->tx_pending)) { entry = list_entry(priv->tx_pending.next, @@ -467,7 +468,7 @@ static int p54spi_wq_tx(struct p54s_priv *priv) list_del_init(&entry->tx_list); - spin_unlock_bh(&priv->tx_lock); + spin_unlock_irqrestore(&priv->tx_lock, flags); dinfo = container_of((void *) entry, struct p54s_tx_info, tx_list); @@ -479,16 +480,14 @@ static int p54spi_wq_tx(struct p54s_priv *priv) ret = p54spi_tx_frame(priv, skb); - spin_lock_bh(&priv->tx_lock); - if (ret < 0) { p54_free_skb(priv->hw, skb); - goto out; + return ret; } - } -out: - spin_unlock_bh(&priv->tx_lock); + spin_lock_irqsave(&priv->tx_lock, flags); + } + spin_unlock_irqrestore(&priv->tx_lock, flags); return ret; } @@ -498,12 +497,13 @@ static void p54spi_op_tx(struct ieee80211_hw *dev, struct sk_buff *skb) struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); struct p54_tx_info *mi = (struct p54_tx_info *) info->rate_driver_data; struct p54s_tx_info *di = (struct p54s_tx_info *) mi->data; + unsigned long flags; BUILD_BUG_ON(sizeof(*di) > sizeof((mi->data))); - spin_lock_bh(&priv->tx_lock); + spin_lock_irqsave(&priv->tx_lock, flags); list_add_tail(&di->tx_list, &priv->tx_pending); - spin_unlock_bh(&priv->tx_lock); + spin_unlock_irqrestore(&priv->tx_lock, flags); queue_work(priv->hw->workqueue, &priv->work); } @@ -604,6 +604,7 @@ out: static void p54spi_op_stop(struct ieee80211_hw *dev) { struct p54s_priv *priv = dev->priv; + unsigned long flags; if (mutex_lock_interruptible(&priv->mutex)) { /* FIXME: how to handle this error? */ @@ -615,9 +616,9 @@ static void p54spi_op_stop(struct ieee80211_hw *dev) cancel_work_sync(&priv->work); p54spi_power_off(priv); - spin_lock_bh(&priv->tx_lock); + spin_lock_irqsave(&priv->tx_lock, flags); INIT_LIST_HEAD(&priv->tx_pending); - spin_unlock_bh(&priv->tx_lock); + spin_unlock_irqrestore(&priv->tx_lock, flags); priv->fw_state = FW_STATE_OFF; mutex_unlock(&priv->mutex); -- 2.7.4