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>

3 files changed, 72 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;
 }
 
diff --git a/drivers/net/wireless/wl12xx/sdio.c b/drivers/net/wireless/wl12xx/sdio.c
index 5b03fd5ee33f..41183db34836 100644
--- a/drivers/net/wireless/wl12xx/sdio.c
+++ b/drivers/net/wireless/wl12xx/sdio.c
@@ -82,6 +82,16 @@ static irqreturn_t wl1271_hardirq(int irq, void *cookie)
                 complete(wl->elp_compl);
                 wl->elp_compl = NULL;
         }
+
+        if (test_bit(WL1271_FLAG_SUSPENDED, &wl->flags)) {
+                /* don't enqueue a work right now. mark it as pending */
+                set_bit(WL1271_FLAG_PENDING_WORK, &wl->flags);
+                wl1271_debug(DEBUG_IRQ, "should not enqueue work");
+                disable_irq_nosync(wl->irq);
+                pm_wakeup_event(wl1271_sdio_wl_to_dev(wl), 0);
+                spin_unlock_irqrestore(&wl->wl_lock, flags);
+                return IRQ_HANDLED;
+        }
         spin_unlock_irqrestore(&wl->wl_lock, flags);
 
         return IRQ_WAKE_THREAD;
@@ -268,6 +278,7 @@ static int __devinit wl1271_probe(struct sdio_func *func,
         }
 
         enable_irq_wake(wl->irq);
+        device_init_wakeup(wl1271_sdio_wl_to_dev(wl), 1);
 
         disable_irq(wl->irq);
 
@@ -305,6 +316,7 @@ static void __devexit wl1271_remove(struct sdio_func *func)
         pm_runtime_get_noresume(&func->dev);
 
         wl1271_unregister_hw(wl);
+        device_init_wakeup(wl1271_sdio_wl_to_dev(wl), 0);
         disable_irq_wake(wl->irq);
         free_irq(wl->irq, wl);
         wl1271_free_hw(wl);
@@ -339,6 +351,9 @@ static int wl1271_suspend(struct device *dev)
                         wl1271_error("error while trying to keep power");
                         goto out;
                 }
+
+                /* release host */
+                sdio_release_host(func);
         }
 out:
         return ret;
@@ -346,6 +361,15 @@ out:
 
 static int wl1271_resume(struct device *dev)
 {
+        struct sdio_func *func = dev_to_sdio_func(dev);
+        struct wl1271 *wl = sdio_get_drvdata(func);
+
+        wl1271_debug(DEBUG_MAC80211, "wl1271 resume");
+        if (wl->wow_enabled) {
+                /* claim back host */
+                sdio_claim_host(func);
+        }
+
         return 0;
 }
 
diff --git a/drivers/net/wireless/wl12xx/wl12xx.h b/drivers/net/wireless/wl12xx/wl12xx.h
index 9629e90d9b55..2218b9c63844 100644
--- a/drivers/net/wireless/wl12xx/wl12xx.h
+++ b/drivers/net/wireless/wl12xx/wl12xx.h
@@ -357,6 +357,8 @@ enum wl12xx_flags {
         WL1271_FLAG_AP_STARTED,
         WL1271_FLAG_IF_INITIALIZED,
         WL1271_FLAG_DUMMY_PACKET_PENDING,
+        WL1271_FLAG_SUSPENDED,
+        WL1271_FLAG_PENDING_WORK,
 };
 
 struct wl1271_link {