ipw2x00: age scan results on resume

Scanned BSS entries are timestamped with jiffies, which doesn't
increment across suspend and hibernate.  On resume, every BSS in the
scan list looks like it was scanned within the last 10 seconds,
irregardless of how long the machine was actually asleep.  Age scan
results on resume with the time spent during sleep so userspace has a
clue how old they really are.

Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ipw2x00/ieee80211.h b/drivers/net/wireless/ipw2x00/ieee80211.h
index adb7cf3..7515fad 100644
--- a/drivers/net/wireless/ipw2x00/ieee80211.h
+++ b/drivers/net/wireless/ipw2x00/ieee80211.h
@@ -1119,6 +1119,9 @@
 extern void free_ieee80211(struct net_device *dev);
 extern struct net_device *alloc_ieee80211(int sizeof_priv);
 
+extern void ieee80211_networks_age(struct ieee80211_device *ieee,
+				   unsigned long age_secs);
+
 extern int ieee80211_set_encryption(struct ieee80211_device *ieee);
 
 /* ieee80211_tx.c */
diff --git a/drivers/net/wireless/ipw2x00/ipw2100.c b/drivers/net/wireless/ipw2x00/ipw2100.c
index 52b1cf5..3a6d810 100644
--- a/drivers/net/wireless/ipw2x00/ipw2100.c
+++ b/drivers/net/wireless/ipw2x00/ipw2100.c
@@ -1692,7 +1692,13 @@
 	u32 lock;
 	u32 ord_len = sizeof(lock);
 
-	/* Quite if manually disabled. */
+	/* Age scan list entries found before suspend */
+	if (priv->suspend_time) {
+		ieee80211_networks_age(priv->ieee, priv->suspend_time);
+		priv->suspend_time = 0;
+	}
+
+	/* Quiet if manually disabled. */
 	if (priv->status & STATUS_RF_KILL_SW) {
 		IPW_DEBUG_INFO("%s: Radio is disabled by Manual Disable "
 			       "switch\n", priv->net_dev->name);
@@ -6415,6 +6421,8 @@
 	pci_disable_device(pci_dev);
 	pci_set_power_state(pci_dev, PCI_D3hot);
 
+	priv->suspend_at = get_seconds();
+
 	mutex_unlock(&priv->action_mutex);
 
 	return 0;
@@ -6458,6 +6466,8 @@
 	 * the queue of needed */
 	netif_device_attach(dev);
 
+	priv->suspend_time = get_seconds() - priv->suspend_at;
+
 	/* Bring the device back up */
 	if (!(priv->status & STATUS_RF_KILL_SW))
 		ipw2100_up(priv, 0);
diff --git a/drivers/net/wireless/ipw2x00/ipw2100.h b/drivers/net/wireless/ipw2x00/ipw2100.h
index 46b135d..f183d95 100644
--- a/drivers/net/wireless/ipw2x00/ipw2100.h
+++ b/drivers/net/wireless/ipw2x00/ipw2100.h
@@ -591,6 +591,10 @@
 
 	int user_requested_scan;
 
+	/* Track time in suspend */
+	unsigned long suspend_at;
+	unsigned long suspend_time;
+
 	u32 interrupts;
 	int tx_interrupts;
 	int rx_interrupts;
diff --git a/drivers/net/wireless/ipw2x00/ipw2200.c b/drivers/net/wireless/ipw2x00/ipw2200.c
index 01c4ede..a7fb08a 100644
--- a/drivers/net/wireless/ipw2x00/ipw2200.c
+++ b/drivers/net/wireless/ipw2x00/ipw2200.c
@@ -11238,6 +11238,12 @@
 {
 	int rc, i, j;
 
+	/* Age scan list entries found before suspend */
+	if (priv->suspend_time) {
+		ieee80211_networks_age(priv->ieee, priv->suspend_time);
+		priv->suspend_time = 0;
+	}
+
 	if (priv->status & STATUS_EXIT_PENDING)
 		return -EIO;
 
@@ -11838,6 +11844,8 @@
 	pci_disable_device(pdev);
 	pci_set_power_state(pdev, pci_choose_state(pdev, state));
 
+	priv->suspend_at = get_seconds();
+
 	return 0;
 }
 
@@ -11873,6 +11881,8 @@
 	 * the queue of needed */
 	netif_device_attach(dev);
 
+	priv->suspend_time = get_seconds() - priv->suspend_at;
+
 	/* Bring the device back up */
 	queue_work(priv->workqueue, &priv->up);
 
diff --git a/drivers/net/wireless/ipw2x00/ipw2200.h b/drivers/net/wireless/ipw2x00/ipw2200.h
index 3e66c99..05e8ccf 100644
--- a/drivers/net/wireless/ipw2x00/ipw2200.h
+++ b/drivers/net/wireless/ipw2x00/ipw2200.h
@@ -1347,6 +1347,10 @@
 
 	s8 tx_power;
 
+	/* Track time in suspend */
+	unsigned long suspend_at;
+	unsigned long suspend_time;
+
 #ifdef CONFIG_PM
 	u32 pm_state[16];
 #endif
diff --git a/drivers/net/wireless/ipw2x00/libipw_module.c b/drivers/net/wireless/ipw2x00/libipw_module.c
index 0f233ab..ec77534 100644
--- a/drivers/net/wireless/ipw2x00/libipw_module.c
+++ b/drivers/net/wireless/ipw2x00/libipw_module.c
@@ -105,6 +105,21 @@
 	ieee->networks = NULL;
 }
 
+void ieee80211_networks_age(struct ieee80211_device *ieee,
+                            unsigned long age_secs)
+{
+	struct ieee80211_network *network = NULL;
+	unsigned long flags;
+	unsigned long age_jiffies = msecs_to_jiffies(age_secs * MSEC_PER_SEC);
+
+	spin_lock_irqsave(&ieee->lock, flags);
+	list_for_each_entry(network, &ieee->network_list, list) {
+		network->last_scanned -= age_jiffies;
+	}
+	spin_unlock_irqrestore(&ieee->lock, flags);
+}
+EXPORT_SYMBOL(ieee80211_networks_age);
+
 static void ieee80211_networks_initialize(struct ieee80211_device *ieee)
 {
 	int i;
diff --git a/drivers/net/wireless/ipw2x00/libipw_rx.c b/drivers/net/wireless/ipw2x00/libipw_rx.c
index 4865475..8d9e96f 100644
--- a/drivers/net/wireless/ipw2x00/libipw_rx.c
+++ b/drivers/net/wireless/ipw2x00/libipw_rx.c
@@ -1616,7 +1616,7 @@
 			break;
 
 		if ((oldest == NULL) ||
-		    (target->last_scanned < oldest->last_scanned))
+		    time_before(target->last_scanned, oldest->last_scanned))
 			oldest = target;
 	}
 
diff --git a/drivers/net/wireless/ipw2x00/libipw_wx.c b/drivers/net/wireless/ipw2x00/libipw_wx.c
index dfbadb3..3c0812d 100644
--- a/drivers/net/wireless/ipw2x00/libipw_wx.c
+++ b/drivers/net/wireless/ipw2x00/libipw_wx.c
@@ -43,6 +43,16 @@
 	"?", "a", "b", "ab", "g", "ag", "bg", "abg"
 };
 
+static inline unsigned int elapsed_jiffies_msecs(unsigned long start)
+{
+	unsigned long end = jiffies;
+
+	if (end >= start)
+		return jiffies_to_msecs(end - start);
+
+	return jiffies_to_msecs(end + (MAX_JIFFY_OFFSET - start) + 1);
+}
+
 #define MAX_CUSTOM_LEN 64
 static char *ieee80211_translate_scan(struct ieee80211_device *ieee,
 				      char *start, char *stop,
@@ -216,8 +226,8 @@
 	iwe.cmd = IWEVCUSTOM;
 	p = custom;
 	p += snprintf(p, MAX_CUSTOM_LEN - (p - custom),
-		      " Last beacon: %dms ago",
-		      jiffies_to_msecs(jiffies - network->last_scanned));
+		      " Last beacon: %ums ago",
+		      elapsed_jiffies_msecs(network->last_scanned));
 	iwe.u.data.length = p - custom;
 	if (iwe.u.data.length)
 		start = iwe_stream_add_point(info, start, stop, &iwe, custom);
@@ -277,15 +287,15 @@
 		    time_after(network->last_scanned + ieee->scan_age, jiffies))
 			ev = ieee80211_translate_scan(ieee, ev, stop, network,
 						      info);
-		else
+		else {
 			IEEE80211_DEBUG_SCAN("Not showing network '%s ("
-					     "%pM)' due to age (%dms).\n",
+					     "%pM)' due to age (%ums).\n",
 					     print_ssid(ssid, network->ssid,
 							 network->ssid_len),
 					     network->bssid,
-					     jiffies_to_msecs(jiffies -
-							      network->
-							      last_scanned));
+					     elapsed_jiffies_msecs(
+					               network->last_scanned));
+		}
 	}
 
 	spin_unlock_irqrestore(&ieee->lock, flags);