From 731c6531684250c46d732e369b25b003356f3947 Mon Sep 17 00:00:00 2001
From: Christian Lamparter <chunkeey@web.de>
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
>[<c0034ff8>] (dump_stack+0x0/0x14)
>[<c005b1a4>] (warn_on_slowpath+0x0/0x68)
>[<c00604c8>] (local_bh_enable+0x0/0xbc)
>[<bf000000>] (p54spi_op_tx+0x0/0x4c [p54spi])
>[<c01a4d34>] (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 <jcmvbkbc@gmail.com>
Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
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 2b222aaa6f0a..d1fe577de3d4 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);