cfg80211/mac80211: disconnect on suspend

If possible that after suspend, cfg80211 will receive request to
disconnect what require action on interface that was removed during
suspend.

Problem can manifest itself by various warnings similar to below one:

WARNING: at net/mac80211/driver-ops.h:12 ieee80211_bss_info_change_notify+0x2f9/0x300 [mac80211]()
wlan0:  Failed check-sdata-in-driver check, flags: 0x4
Call Trace:
 [<c043e0b3>] warn_slowpath_fmt+0x33/0x40
 [<f83707c9>] ieee80211_bss_info_change_notify+0x2f9/0x300 [mac80211]
 [<f83a660a>] ieee80211_recalc_ps_vif+0x2a/0x30 [mac80211]
 [<f83a6706>] ieee80211_set_disassoc+0xf6/0x500 [mac80211]
 [<f83a9441>] ieee80211_mgd_deauth+0x1f1/0x280 [mac80211]
 [<f8381b36>] ieee80211_deauth+0x16/0x20 [mac80211]
 [<f8261e70>] cfg80211_mlme_down+0x70/0xc0 [cfg80211]
 [<f8264de1>] __cfg80211_disconnect+0x1b1/0x1d0 [cfg80211]

To fix the problem disconnect from any associated network before
suspend. User space is responsible to establish connection again
after resume. This basically need to be done by user space anyway,
because associated stations can go away during suspend (for example
NetworkManager disconnects on suspend and connect on resume by default).

Patch also handle situation when driver refuse to suspend with wowlan
configured and try to suspend again without it.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 20 insertions, 5 deletions

diff --git a/net/wireless/sysfs.c b/net/wireless/sysfs.c
index 238ee49b3868..8f28b9f798d8 100644
--- a/net/wireless/sysfs.c
+++ b/net/wireless/sysfs.c
@@ -83,6 +83,14 @@ static int wiphy_uevent(struct device *dev, struct kobj_uevent_env *env)
 	return 0;
 }
 
+static void cfg80211_leave_all(struct cfg80211_registered_device *rdev)
+{
+	struct wireless_dev *wdev;
+
+	list_for_each_entry(wdev, &rdev->wdev_list, list)
+		cfg80211_leave(rdev, wdev);
+}
+
 static int wiphy_suspend(struct device *dev, pm_message_t state)
 {
 	struct cfg80211_registered_device *rdev = dev_to_rdev(dev);
@@ -90,12 +98,19 @@ static int wiphy_suspend(struct device *dev, pm_message_t state)
 
 	rdev->suspend_at = get_seconds();
 
-	if (rdev->ops->suspend) {
-		rtnl_lock();
-		if (rdev->wiphy.registered)
-			ret = rdev_suspend(rdev);
-		rtnl_unlock();
+	rtnl_lock();
+	if (rdev->wiphy.registered) {
+		if (!rdev->wowlan)
+			cfg80211_leave_all(rdev);
+		if (rdev->ops->suspend)
+			ret = rdev_suspend(rdev, rdev->wowlan);
+		if (ret == 1) {
+			/* Driver refuse to configure wowlan */
+			cfg80211_leave_all(rdev);
+			ret = rdev_suspend(rdev, NULL);
+		}
 	}
+	rtnl_unlock();
 
 	return ret;
 }