wlcore: fixes for connection_loss_work

We can't use cancel_delayed_work_sync() from functions that take the
wl->mutex, since connection_loss_work also takes the mutex. This might
result in a deadlock. Restructure the code so the work is synchronously
canceled before taking the mutex.
Avoid a bug where we would indefinitely delay the connection loss
indication by re-queuing the connection loss work on consecutive beacon
loss events.

Cc: bartosz.markowski <bartosz.markowski@tieto.com>
Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

2 files changed, 19 insertions, 6 deletions

diff --git a/drivers/net/wireless/ti/wlcore/event.c b/drivers/net/wireless/ti/wlcore/event.c
index 28e2a633c3be..4ed835799178 100644
--- a/drivers/net/wireless/ti/wlcore/event.c
+++ b/drivers/net/wireless/ti/wlcore/event.c
@@ -148,15 +148,24 @@ static int wl1271_event_process(struct wl1271 *wl)
                 int delay = wl->conf.conn.synch_fail_thold *
                                         wl->conf.conn.bss_lose_timeout;
                 wl1271_info("Beacon loss detected.");
-                cancel_delayed_work_sync(&wl->connection_loss_work);
+
+                /*
+                 * if the work is already queued, it should take place. We
+                 * don't want to delay the connection loss indication
+                 * any more.
+                 */
                 ieee80211_queue_delayed_work(wl->hw, &wl->connection_loss_work,
-                      msecs_to_jiffies(delay));
+                                             msecs_to_jiffies(delay));
         }
 
         if (vector & REGAINED_BSS_EVENT_ID) {
                 /* TODO: check for multi-role */
                 wl1271_info("Beacon regained.");
-                cancel_delayed_work_sync(&wl->connection_loss_work);
+                cancel_delayed_work(&wl->connection_loss_work);
+
+                /* sanity check - we can't lose and gain the beacon together */
+                WARN(vector & BSS_LOSE_EVENT_ID,
+                     "Concurrent beacon loss and gain from FW");
         }
 
         if (vector & RSSI_SNR_TRIGGER_0_EVENT_ID) {
diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
index af00dabf96b7..4be62c93808b 100644
--- a/drivers/net/wireless/ti/wlcore/main.c
+++ b/drivers/net/wireless/ti/wlcore/main.c
@@ -3712,9 +3712,6 @@ sta_not_found:
                         do_join = true;
                         set_assoc = true;
 
-                        /* Cancel connection_loss_work */
-                        cancel_delayed_work_sync(&wl->connection_loss_work);
-
                         /*
                          * use basic rates from AP, and determine lowest rate
                          * to use with control frames.
@@ -3964,6 +3961,13 @@ static void wl1271_op_bss_info_changed(struct ieee80211_hw *hw,
         wl1271_debug(DEBUG_MAC80211, "mac80211 bss info changed 0x%x",
                      (int)changed);
 
+        /*
+         * make sure to cancel pending disconnections if our association
+         * state changed
+         */
+        if (!is_ap && (changed & BSS_CHANGED_ASSOC))
+                cancel_delayed_work_sync(&wl->connection_loss_work);
+
         mutex_lock(&wl->mutex);
 
         if (unlikely(wl->state == WL1271_STATE_OFF))