wl12xx: prevent scheduling while suspending (WoW enabled)

When WoW is enabled, the interface will stay up and the chip will
be powered on, so we have to flush/cancel any remaining work, and
prevent the irq handler from scheduling a new work until the system
is resumed.

Add 2 new flags:
* WL1271_FLAG_SUSPENDED - the system is (about to be) suspended.
* WL1271_FLAG_PENDING_WORK - there is a pending irq work which
   should be scheduled when the system is being resumed.

In order to wake-up the system while getting an irq, we initialize
the device as wakeup device, and calling pm_wakeup_event() upon
getting the interrupt (while the system is about to be suspended)

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c
index 4b421d801873..8f9e6152f3b7 100644
--- a/drivers/net/wireless/wl12xx/main.c
+++ b/drivers/net/wireless/wl12xx/main.c
@@ -1356,6 +1356,28 @@ static int wl1271_op_suspend(struct ieee80211_hw *hw,
         struct wl1271 *wl = hw->priv;
         wl1271_debug(DEBUG_MAC80211, "mac80211 suspend wow=%d", !!wow);
         wl->wow_enabled = !!wow;
+        if (wl->wow_enabled) {
+                /* flush any remaining work */
+                wl1271_debug(DEBUG_MAC80211, "flushing remaining works");
+                flush_delayed_work(&wl->scan_complete_work);
+
+                /*
+                 * disable and re-enable interrupts in order to flush
+                 * the threaded_irq
+                 */
+                wl1271_disable_interrupts(wl);
+
+                /*
+                 * set suspended flag to avoid triggering a new threaded_irq
+                 * work. no need for spinlock as interrupts are disabled.
+                 */
+                set_bit(WL1271_FLAG_SUSPENDED, &wl->flags);
+
+                wl1271_enable_interrupts(wl);
+                flush_work(&wl->tx_work);
+                flush_delayed_work(&wl->pspoll_work);
+                flush_delayed_work(&wl->elp_work);
+        }
         return 0;
 }
 
@@ -1364,6 +1386,30 @@ static int wl1271_op_resume(struct ieee80211_hw *hw)
         struct wl1271 *wl = hw->priv;
         wl1271_debug(DEBUG_MAC80211, "mac80211 resume wow=%d",
                      wl->wow_enabled);
+
+        /*
+         * re-enable irq_work enqueuing, and call irq_work directly if
+         * there is a pending work.
+         */
+        if (wl->wow_enabled) {
+                struct wl1271 *wl = hw->priv;
+                unsigned long flags;
+                bool run_irq_work = false;
+
+                spin_lock_irqsave(&wl->wl_lock, flags);
+                clear_bit(WL1271_FLAG_SUSPENDED, &wl->flags);
+                if (test_and_clear_bit(WL1271_FLAG_PENDING_WORK, &wl->flags))
+                        run_irq_work = true;
+                spin_unlock_irqrestore(&wl->wl_lock, flags);
+
+                if (run_irq_work) {
+                        wl1271_debug(DEBUG_MAC80211,
+                                     "run postponed irq_work directly");
+                        wl1271_irq(0, wl);
+                        wl1271_enable_interrupts(wl);
+                }
+        }
+
         return 0;
 }