cw1200: Cancel suspend on late interrupts.

 * Code added to detect late (after suspend) interrupts and cancel
   suspend in that case. Applicable only for GPIO IRQs.
   Similar modification is required in the MMC/SDIO driver to handle
   late SDIO IRQs properly.
 * Code added to hold wakelock for 1 sec. when frame is sent from
   the driver up to userspace.

Change-Id: Ia739c243164a6d35602dc9f634d3990214560eb9
Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/28850
Reviewed-by: Bartosz MARKOWSKI <bartosz.markowski@tieto.com>
Tested-by: Bartosz MARKOWSKI <bartosz.markowski@tieto.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/29061
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/33507
Reviewed-by: Philippe LANGLAIS <philippe.langlais@stericsson.com>

5 files changed, 156 insertions, 6 deletions

diff --git a/drivers/staging/cw1200/cw1200.h b/drivers/staging/cw1200/cw1200.h
index 9bb68541035..80eb3c49f81 100644
--- a/drivers/staging/cw1200/cw1200.h
+++ b/drivers/staging/cw1200/cw1200.h
@@ -29,11 +29,11 @@
 #include "scan.h"
 #include "txrx.h"
 #include "ht.h"
+#include "pm.h"
 
 /* extern */ struct sbus_ops;
 /* extern */ struct task_struct;
 /* extern */ struct cw1200_debug_priv;
-/* extern */ struct cw1200_suspend_state;
 /* extern */ struct firmware;
 
 #if defined(CONFIG_CW1200_TXRX_DEBUG)
@@ -116,7 +116,7 @@ struct cw1200_common {
 	struct wsm_beacon_filter_control bf_control;
 	u8				ba_tid_mask;
 	struct wsm_multicast_filter	multicast_filter;
-	struct cw1200_suspend_state	*suspend_state;
+	struct cw1200_pm_state		pm_state;
 	struct wsm_p2p_ps_modeinfo	p2p_ps_modeinfo;
 
 	/* BH */
diff --git a/drivers/staging/cw1200/main.c b/drivers/staging/cw1200/main.c
index cddb9943ee6..8ba8629cb03 100644
--- a/drivers/staging/cw1200/main.c
+++ b/drivers/staging/cw1200/main.c
@@ -349,6 +349,7 @@ struct ieee80211_hw *cw1200_init_common(size_t priv_data_len)
 	init_waitqueue_head(&priv->wsm_startup_done);
 	wsm_buf_init(&priv->wsm_cmd_buf);
 	tx_policy_init(priv);
+	cw1200_pm_init(&priv->pm_state, priv);
 
 	return hw;
 }
@@ -429,6 +430,7 @@ void cw1200_unregister_common(struct ieee80211_hw *dev)
 	for (i = 0; i < 4; ++i)
 		cw1200_queue_deinit(&priv->tx_queue[i]);
 	cw1200_queue_stats_deinit(&priv->tx_queue_stats);
+	cw1200_pm_deinit(&priv->pm_state);
 }
 EXPORT_SYMBOL_GPL(cw1200_unregister_common);
 
diff --git a/drivers/staging/cw1200/pm.c b/drivers/staging/cw1200/pm.c
index 72f11e09d50..e27c4144f51 100644
--- a/drivers/staging/cw1200/pm.c
+++ b/drivers/staging/cw1200/pm.c
@@ -9,12 +9,15 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/platform_device.h>
 #include "cw1200.h"
 #include "pm.h"
 #include "sta.h"
 #include "bh.h"
 #include "sbus.h"
 
+static int cw1200_suspend_late(struct device *dev);
+
 /* private */
 struct cw1200_suspend_state {
 	unsigned long bss_loss_tmo;
@@ -22,6 +25,94 @@ struct cw1200_suspend_state {
 	unsigned long join_tmo;
 };
 
+static struct dev_pm_ops cw1200_pm_ops = {
+	.suspend_noirq = cw1200_suspend_late,
+};
+static struct platform_driver cw1200_power_driver = {
+	.driver.name = "cw1200_power",
+	.driver.pm = &cw1200_pm_ops,
+};
+static struct platform_device cw1200_power_device = {
+	.name = "cw1200_power",
+};
+
+static void cw1200_pm_init_common(struct cw1200_pm_state *pm,
+				  struct cw1200_common *priv)
+{
+	spin_lock_init(&pm->lock);
+	cw1200_power_device.dev.platform_data = priv;
+	platform_device_register(&cw1200_power_device);
+	platform_driver_register(&cw1200_power_driver);
+}
+
+static void cw1200_pm_deinit_common(struct cw1200_pm_state *pm)
+{
+	platform_driver_unregister(&cw1200_power_driver);
+	platform_device_unregister(&cw1200_power_device);
+}
+
+#ifdef CONFIG_WAKELOCK
+
+void cw1200_pm_init(struct cw1200_pm_state *pm,
+		    struct cw1200_common *priv)
+{
+	cw1200_pm_init_common(pm, priv);
+	wake_lock_init(&pm->wakelock,
+		WAKE_LOCK_SUSPEND, "cw1200_wlan");
+}
+
+void cw1200_pm_deinit(struct cw1200_pm_state *pm)
+{
+	if (wake_lock_active(&pm->wakelock))
+		wake_unlock(&pm->wakelock);
+	wake_lock_destroy(&pm->wakelock);
+	cw1200_pm_deinit_common(pm);
+}
+void cw1200_pm_stay_awake(struct cw1200_pm_state *pm,
+			  unsigned long tmo)
+{
+	long cur_tmo;
+	spin_lock_bh(&pm->lock);
+	cur_tmo = pm->wakelock.expires - jiffies;
+	if (!wake_lock_active(&pm->wakelock) ||
+			cur_tmo < (long)tmo)
+		wake_lock_timeout(&pm->wakelock, tmo);
+	spin_unlock_bh(&pm->lock);
+}
+
+#else /* CONFIG_WAKELOCK */
+
+static void cw1200_pm_stay_awake_tmo(unsigned long)
+{
+}
+
+void cw1200_pm_init(struct cw1200_pm_state *pm)
+{
+	cw1200_init_common(pm);
+	init_timer(&pm->stay_awake);
+	pm->stay_awake.data = (unsigned long)pm;
+	pm->stay_awake.function = cw1200_pm_stay_awake_tmo;
+}
+
+void cw1200_pm_deinit(struct cw1200_pm_state *pm)
+{
+	del_timer_sync(&pm->stay_awake);
+}
+
+void cw1200_pm_stay_awake(struct cw1200_pm_state *pm,
+			  unsigned long tmo)
+{
+	long cur_tmo;
+	spin_lock_bh(&pm->lock);
+	cur_tmo = pm->stay_awake.expires - jiffies;
+	if (!timer_pending(&pm->stay_awake) ||
+			cur_tmo < (long)tmo)
+		mod_timer(&pm->stay_awake, jiffies + tmo);
+	spin_unlock_bh(&pm->lock);
+}
+
+#endif /* CONFIG_WAKELOCK */
+
 static long cw1200_suspend_work(struct delayed_work *work)
 {
 	int ret = cancel_delayed_work(work);
@@ -47,12 +138,33 @@ static int cw1200_resume_work(struct cw1200_common *priv,
 	return queue_delayed_work(priv->workqueue, work, tmo);
 }
 
+static int cw1200_suspend_late(struct device *dev)
+{
+	struct cw1200_common *priv = dev->platform_data;
+	if (atomic_read(&priv->bh_rx)) {
+		wiphy_dbg(priv->hw->wiphy,
+			"%s: Suspend interrupted.\n",
+			__func__);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
 int cw1200_wow_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 {
 	struct cw1200_common *priv = hw->priv;
+	struct cw1200_pm_state *pm_state = &priv->pm_state;
 	struct cw1200_suspend_state *state;
 	int ret;
 
+#ifndef CONFIG_WAKELOCK
+	spin_lock_bh(&pm->lock);
+	ret = timer_pending(&pm->stay_awake);
+	spin_unlock_bh(&pm->lock);
+	if (ret)
+		return -EAGAIN;
+#endif
+
 	/* Ensure pending operations are done. */
 	ret = wait_event_interruptible_timeout(
 		priv->channel_switch_done,
@@ -89,7 +201,7 @@ int cw1200_wow_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 	cw1200_bh_suspend(priv);
 
 	/* Store suspend state */
-	priv->suspend_state = state;
+	pm_state->suspend_state = state;
 
 	/* Enable IRQ wake */
 	ret = priv->sbus_ops->power_mgmt(priv->sbus_priv, true);
@@ -113,10 +225,11 @@ int cw1200_wow_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 int cw1200_wow_resume(struct ieee80211_hw *hw)
 {
 	struct cw1200_common *priv = hw->priv;
+	struct cw1200_pm_state *pm_state = &priv->pm_state;
 	struct cw1200_suspend_state *state;
 
-	state = priv->suspend_state;
-	priv->suspend_state = NULL;
+	state = pm_state->suspend_state;
+	pm_state->suspend_state = NULL;
 
 	/* Disable IRQ wake */
 	priv->sbus_ops->power_mgmt(priv->sbus_priv, false);
diff --git a/drivers/staging/cw1200/pm.h b/drivers/staging/cw1200/pm.h
index 841b609457f..433e5ec1139 100644
--- a/drivers/staging/cw1200/pm.h
+++ b/drivers/staging/cw1200/pm.h
@@ -12,12 +12,37 @@
 #ifndef PM_H_INCLUDED
 #define PM_H_INCLUDED
 
+#ifdef CONFIG_WAKELOCK
+#include <linux/wakelock.h>
+#endif
+
 /* ******************************************************************** */
 /* mac80211 API								*/
 
 #ifdef CONFIG_PM
-int cw1200_wow_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan);
+
+/* extern */  struct cw1200_common;
+/* private */ struct cw1200_suspend_state;
+
+struct cw1200_pm_state {
+	struct cw1200_suspend_state *suspend_state;
+#ifdef CONFIG_WAKELOCK
+	struct wake_lock wakelock;
+#else
+	struct timer_list stay_awake;
+#endif
+	spinlock_t lock;
+};
+
+void cw1200_pm_init(struct cw1200_pm_state *pm,
+		    struct cw1200_common *priv);
+void cw1200_pm_deinit(struct cw1200_pm_state *pm);
+void cw1200_pm_stay_awake(struct cw1200_pm_state *pm,
+			  unsigned long tmo);
+int cw1200_wow_suspend(struct ieee80211_hw *hw,
+		       struct cfg80211_wowlan *wowlan);
 int cw1200_wow_resume(struct ieee80211_hw *hw);
+
 #endif /* CONFIG_PM */
 
 #endif
diff --git a/drivers/staging/cw1200/txrx.c b/drivers/staging/cw1200/txrx.c
index 5201ffe65ab..18544011b16 100644
--- a/drivers/staging/cw1200/txrx.c
+++ b/drivers/staging/cw1200/txrx.c
@@ -719,6 +719,7 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 {
 	struct sk_buff *skb = *skb_p;
 	struct ieee80211_rx_status *hdr = IEEE80211_SKB_RXCB(skb);
+	unsigned long grace_period;
 	__le16 frame_control;
 	hdr->flag = 0;
 
@@ -825,6 +826,15 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 		if (cw1200_handle_action_rx(priv, skb))
 			return;
 
+	/* Stay awake for 1sec. after frame is received to give
+	 * userspace chance to react and acquire appropriate
+	 * wakelock. */
+	if (ieee80211_is_auth(frame_control))
+		grace_period = 5 * HZ;
+	else
+		grace_period = 1 * HZ;
+	cw1200_pm_stay_awake(&priv->pm_state, grace_period);
+
 	/* Not that we really need _irqsafe variant here,
 	 * but it offloads realtime bh thread and improve
 	 * system performance. */