Revert "NET: Fix locking issues in PPP, 6pack, mkiss and strip line disciplines."

This reverts commit adeab1afb7de89555c69aab5ca21300c14af6369.

As Alan Cox explained, the TTY layer changes that went recently
to get rid of the tty->low_latency stuff fixes this already,
and even for -stable it's the ->low_latency changes that should
go in to fix this, rather than this patch.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 913a564..1551600 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -398,14 +398,13 @@
                                                                                 
 static struct sixpack *sp_get(struct tty_struct *tty)
 {
-	unsigned long flags;
 	struct sixpack *sp;
 
-	read_lock_irqsave(&disc_data_lock, flags);
+	read_lock(&disc_data_lock);
 	sp = tty->disc_data;
 	if (sp)
 		atomic_inc(&sp->refcnt);
-	read_unlock_irqrestore(&disc_data_lock, flags);
+	read_unlock(&disc_data_lock);
 
 	return sp;
 }
@@ -689,13 +688,12 @@
  */
 static void sixpack_close(struct tty_struct *tty)
 {
-	unsigned long flags;
 	struct sixpack *sp;
 
-	write_lock_irqsave(&disc_data_lock, flags);
+	write_lock(&disc_data_lock);
 	sp = tty->disc_data;
 	tty->disc_data = NULL;
-	write_unlock_irqrestore(&disc_data_lock, flags);
+	write_unlock(&disc_data_lock);
 	if (!sp)
 		return;
 
diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index a728650..fda2fc8 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -244,16 +244,15 @@
 /* Send one completely decapsulated AX.25 packet to the AX.25 layer. */
 static void ax_bump(struct mkiss *ax)
 {
-	unsigned long flags;
 	struct sk_buff *skb;
 	int count;
 
-	spin_lock_irqsave(&ax->buflock, flags);
+	spin_lock_bh(&ax->buflock);
 	if (ax->rbuff[0] > 0x0f) {
 		if (ax->rbuff[0] & 0x80) {
 			if (check_crc_16(ax->rbuff, ax->rcount) < 0) {
 				ax->dev->stats.rx_errors++;
-				spin_unlock_irqrestore(&ax->buflock, flags);
+				spin_unlock_bh(&ax->buflock);
 
 				return;
 			}
@@ -268,7 +267,7 @@
 		} else if (ax->rbuff[0] & 0x20)  {
 			if (check_crc_flex(ax->rbuff, ax->rcount) < 0) {
 				ax->dev->stats.rx_errors++;
-				spin_unlock_irqrestore(&ax->buflock, flags);
+				spin_unlock_bh(&ax->buflock);
 				return;
 			}
 			if (ax->crcmode != CRC_MODE_FLEX && ax->crcauto) {
@@ -295,7 +294,7 @@
 		printk(KERN_ERR "mkiss: %s: memory squeeze, dropping packet.\n",
 		       ax->dev->name);
 		ax->dev->stats.rx_dropped++;
-		spin_unlock_irqrestore(&ax->buflock, flags);
+		spin_unlock_bh(&ax->buflock);
 		return;
 	}
 
@@ -304,13 +303,11 @@
 	netif_rx(skb);
 	ax->dev->stats.rx_packets++;
 	ax->dev->stats.rx_bytes += count;
-	spin_unlock_irqrestore(&ax->buflock, flags);
+	spin_unlock_bh(&ax->buflock);
 }
 
 static void kiss_unesc(struct mkiss *ax, unsigned char s)
 {
-	unsigned long flags;
-
 	switch (s) {
 	case END:
 		/* drop keeptest bit = VSV */
@@ -337,18 +334,18 @@
 		break;
 	}
 
-	spin_lock_irqsave(&ax->buflock, flags);
+	spin_lock_bh(&ax->buflock);
 	if (!test_bit(AXF_ERROR, &ax->flags)) {
 		if (ax->rcount < ax->buffsize) {
 			ax->rbuff[ax->rcount++] = s;
-			spin_unlock_irqrestore(&ax->buflock, flags);
+			spin_unlock_bh(&ax->buflock);
 			return;
 		}
 
 		ax->dev->stats.rx_over_errors++;
 		set_bit(AXF_ERROR, &ax->flags);
 	}
-	spin_unlock_irqrestore(&ax->buflock, flags);
+	spin_unlock_bh(&ax->buflock);
 }
 
 static int ax_set_mac_address(struct net_device *dev, void *addr)
@@ -370,7 +367,6 @@
 {
 	struct net_device *dev = ax->dev;
 	unsigned char *xbuff, *rbuff, *oxbuff, *orbuff;
-	unsigned long flags;
 	int len;
 
 	len = dev->mtu * 2;
@@ -396,7 +392,7 @@
 		return;
 	}
 
-	spin_lock_irqsave(&ax->buflock, flags);
+	spin_lock_bh(&ax->buflock);
 
 	oxbuff    = ax->xbuff;
 	ax->xbuff = xbuff;
@@ -427,7 +423,7 @@
 	ax->mtu      = dev->mtu + 73;
 	ax->buffsize = len;
 
-	spin_unlock_irqrestore(&ax->buflock, flags);
+	spin_unlock_bh(&ax->buflock);
 
 	kfree(oxbuff);
 	kfree(orbuff);
@@ -437,7 +433,6 @@
 static void ax_encaps(struct net_device *dev, unsigned char *icp, int len)
 {
 	struct mkiss *ax = netdev_priv(dev);
-	unsigned long flags;
 	unsigned char *p;
 	int actual, count;
 
@@ -454,7 +449,7 @@
 
 	p = icp;
 
-	spin_lock_irqsave(&ax->buflock, flags);
+	spin_lock_bh(&ax->buflock);
 	if ((*p & 0x0f) != 0) {
 		/* Configuration Command (kissparms(1).
 		 * Protocol spec says: never append CRC.
@@ -484,7 +479,7 @@
 				ax->crcauto = (cmd ? 0 : 1);
 				printk(KERN_INFO "mkiss: %s: crc mode %s %d\n", ax->dev->name, (len) ? "set to" : "is", cmd);
 			}
-			spin_unlock_irqrestore(&ax->buflock, flags);
+			spin_unlock_bh(&ax->buflock);
 			netif_start_queue(dev);
 
 			return;
@@ -517,7 +512,7 @@
 			count = kiss_esc(p, (unsigned char *)ax->xbuff, len);
 		}
   	}
-	spin_unlock_irqrestore(&ax->buflock, flags);
+	spin_unlock_bh(&ax->buflock);
 
 	set_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags);
 	actual = ax->tty->ops->write(ax->tty, ax->xbuff, count);
@@ -709,14 +704,13 @@
 
 static struct mkiss *mkiss_get(struct tty_struct *tty)
 {
-	unsigned long flags;
 	struct mkiss *ax;
 
-	read_lock_irqsave(&disc_data_lock, flags);
+	read_lock(&disc_data_lock);
 	ax = tty->disc_data;
 	if (ax)
 		atomic_inc(&ax->refcnt);
-	read_unlock_irqrestore(&disc_data_lock, flags);
+	read_unlock(&disc_data_lock);
 
 	return ax;
 }
@@ -815,13 +809,12 @@
 
 static void mkiss_close(struct tty_struct *tty)
 {
-	unsigned long flags;
 	struct mkiss *ax;
 
-	write_lock_irqsave(&disc_data_lock, flags);
+	write_lock(&disc_data_lock);
 	ax = tty->disc_data;
 	tty->disc_data = NULL;
-	write_unlock_irqrestore(&disc_data_lock, flags);
+	write_unlock(&disc_data_lock);
 
 	if (!ax)
 		return;
diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c
index 1fd319b..17c116b 100644
--- a/drivers/net/ppp_async.c
+++ b/drivers/net/ppp_async.c
@@ -132,15 +132,13 @@
 
 static struct asyncppp *ap_get(struct tty_struct *tty)
 {
-	unsigned long flags;
 	struct asyncppp *ap;
 
-	read_lock_irqsave(&disc_data_lock, flags);
+	read_lock(&disc_data_lock);
 	ap = tty->disc_data;
 	if (ap != NULL)
 		atomic_inc(&ap->refcnt);
-	read_unlock_irqrestore(&disc_data_lock, flags);
-
+	read_unlock(&disc_data_lock);
 	return ap;
 }
 
@@ -217,13 +215,12 @@
 static void
 ppp_asynctty_close(struct tty_struct *tty)
 {
-	unsigned long flags;
 	struct asyncppp *ap;
 
-	write_lock_irqsave(&disc_data_lock, flags);
+	write_lock_irq(&disc_data_lock);
 	ap = tty->disc_data;
 	tty->disc_data = NULL;
-	write_unlock_irqrestore(&disc_data_lock, flags);
+	write_unlock_irq(&disc_data_lock);
 	if (!ap)
 		return;
 
diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c
index 1b3f75f..aa3d39f 100644
--- a/drivers/net/ppp_synctty.c
+++ b/drivers/net/ppp_synctty.c
@@ -182,15 +182,13 @@
 
 static struct syncppp *sp_get(struct tty_struct *tty)
 {
-	unsigned long flags;
 	struct syncppp *ap;
 
-	read_lock_irqsave(&disc_data_lock, flags);
+	read_lock(&disc_data_lock);
 	ap = tty->disc_data;
 	if (ap != NULL)
 		atomic_inc(&ap->refcnt);
-	read_unlock_irqrestore(&disc_data_lock, flags);
-
+	read_unlock(&disc_data_lock);
 	return ap;
 }
 
@@ -264,13 +262,12 @@
 static void
 ppp_sync_close(struct tty_struct *tty)
 {
-	unsigned long flags;
 	struct syncppp *ap;
 
-	write_lock_irqsave(&disc_data_lock, flags);
+	write_lock_irq(&disc_data_lock);
 	ap = tty->disc_data;
 	tty->disc_data = NULL;
-	write_unlock_irqrestore(&disc_data_lock, flags);
+	write_unlock_irq(&disc_data_lock);
 	if (!ap)
 		return;
 
diff --git a/drivers/net/wireless/strip.c b/drivers/net/wireless/strip.c
index 3d39f65..38366a5 100644
--- a/drivers/net/wireless/strip.c
+++ b/drivers/net/wireless/strip.c
@@ -856,7 +856,6 @@
 	unsigned char *orbuff = strip_info->rx_buff;
 	unsigned char *osbuff = strip_info->sx_buff;
 	unsigned char *otbuff = strip_info->tx_buff;
-	unsigned long flags;
 
 	if (new_mtu > MAX_SEND_MTU) {
 		printk(KERN_ERR
@@ -865,11 +864,11 @@
 		return -EINVAL;
 	}
 
-	spin_lock_irqsave(&strip_lock, flags);
+	spin_lock_bh(&strip_lock);
 	if (!allocate_buffers(strip_info, new_mtu)) {
 		printk(KERN_ERR "%s: unable to grow strip buffers, MTU change cancelled.\n",
 		       strip_info->dev->name);
-		spin_unlock_irqrestore(&strip_lock, flags);
+		spin_unlock_bh(&strip_lock);
 		return -ENOMEM;
 	}
 
@@ -893,7 +892,7 @@
 		}
 	}
 	strip_info->tx_head = strip_info->tx_buff;
-	spin_unlock_irqrestore(&strip_lock, flags);
+	spin_unlock_bh(&strip_lock);
 
 	printk(KERN_NOTICE "%s: strip MTU changed fom %d to %d.\n",
 	       strip_info->dev->name, old_mtu, strip_info->mtu);
@@ -984,13 +983,10 @@
 			   const MetricomNodeTable * table,
 			   const char *title)
 {
-	unsigned long flags;
+	/* We wrap this in a do/while loop, so if the table changes */
+	/* while we're reading it, we just go around and try again. */
 	struct timeval t;
 
-	/*
-	 * We wrap this in a do/while loop, so if the table changes
-	 * while we're reading it, we just go around and try again.
-	 */
 	do {
 		int i;
 		t = table->timestamp;
@@ -999,9 +995,9 @@
 		for (i = 0; i < table->num_nodes; i++) {
 			MetricomNode node;
 
-			spin_lock_irqsave(&strip_lock, flags);
+			spin_lock_bh(&strip_lock);
 			node = table->node[i];
-			spin_unlock_irqrestore(&strip_lock, flags);
+			spin_unlock_bh(&strip_lock);
 			seq_printf(seq, "  %s\n", node.c);
 		}
 	} while (table->timestamp.tv_sec != t.tv_sec
@@ -1540,7 +1536,6 @@
 static int strip_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct strip *strip_info = netdev_priv(dev);
-	unsigned long flags;
 
 	if (!netif_running(dev)) {
 		printk(KERN_ERR "%s: xmit call when iface is down\n",
@@ -1579,11 +1574,11 @@
 			       strip_info->dev->name, sx_pps_count / 8);
 	}
 
-	spin_lock_irqsave(&strip_lock, flags);
+	spin_lock_bh(&strip_lock);
 
 	strip_send(strip_info, skb);
 
-	spin_unlock_irqrestore(&strip_lock, flags);
+	spin_unlock_bh(&strip_lock);
 
 	if (skb)
 		dev_kfree_skb(skb);
@@ -2268,13 +2263,12 @@
 {
 	struct strip *strip_info = tty->disc_data;
 	const unsigned char *end = cp + count;
-	unsigned long flags;
 
 	if (!strip_info || strip_info->magic != STRIP_MAGIC
 	    || !netif_running(strip_info->dev))
 		return;
 
-	spin_lock_irqsave(&strip_lock, flags);
+	spin_lock_bh(&strip_lock);
 #if 0
 	{
 		struct timeval tv;
@@ -2341,7 +2335,7 @@
 		}
 		cp++;
 	}
-	spin_unlock_irqrestore(&strip_lock, flags);
+	spin_unlock_bh(&strip_lock);
 }
 
 
@@ -2529,11 +2523,9 @@
 
 static void strip_free(struct strip *strip_info)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&strip_lock, flags);
+	spin_lock_bh(&strip_lock);
 	list_del_rcu(&strip_info->list);
-	spin_unlock_irqrestore(&strip_lock, flags);
+	spin_unlock_bh(&strip_lock);
 
 	strip_info->magic = 0;
 
@@ -2547,7 +2539,6 @@
 static struct strip *strip_alloc(void)
 {
 	struct list_head *n;
-	unsigned long flags;
 	struct net_device *dev;
 	struct strip *strip_info;
 
@@ -2571,7 +2562,7 @@
 	strip_info->idle_timer.function = strip_IdleTask;
 
 
-	spin_lock_irqsave(&strip_lock, flags);
+	spin_lock_bh(&strip_lock);
  rescan:
 	/*
 	 * Search the list to find where to put our new entry
@@ -2590,7 +2581,7 @@
 	sprintf(dev->name, "st%ld", dev->base_addr);
 
 	list_add_tail_rcu(&strip_info->list, &strip_list);
-	spin_unlock_irqrestore(&strip_lock, flags);
+	spin_unlock_bh(&strip_lock);
 
 	return strip_info;
 }