Bluetooth: Hold wakelock until BT idle timer kicks in.

Holding a wakelock avoids suspend power collapse, which
allow the BT idle timer to kick in, which eventually
initiates BT low power modes.

CRs-Fixed: 361067
Change-Id: I93e3950b6f854e70dbce092a5529120ec008c2b8
Signed-off-by: Rahul Kashyap <rkashyap@codeaurora.org>
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 5749293..47b856c 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -26,7 +26,7 @@
 #define __HCI_CORE_H
 
 #include <net/bluetooth/hci.h>
-
+#include <linux/wakelock.h>
 /* HCI upper protocols */
 #define HCI_PROTO_L2CAP	0
 #define HCI_PROTO_SCO	1
@@ -326,7 +326,7 @@
 
 	struct work_struct work_add;
 	struct work_struct work_del;
-
+	struct wake_lock idle_lock;
 	struct device	dev;
 	atomic_t	devref;
 
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 25b559b1..02ea082 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -448,6 +448,7 @@
 
 	conn->power_save = 1;
 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;
+	wake_lock_init(&conn->idle_lock, WAKE_LOCK_SUSPEND, "bt_idle");
 
 	switch (type) {
 	case ACL_LINK:
@@ -521,6 +522,7 @@
 
 	/* Make sure no timers are running */
 	del_timer(&conn->idle_timer);
+	wake_lock_destroy(&conn->idle_lock);
 	del_timer(&conn->disc_timer);
 	del_timer(&conn->smp_timer);
 	__cancel_delayed_work(&conn->rssi_update_work);
@@ -962,9 +964,11 @@
 	}
 
 timer:
-	if (hdev->idle_timeout > 0)
+	if (hdev->idle_timeout > 0) {
 		mod_timer(&conn->idle_timer,
 			jiffies + msecs_to_jiffies(hdev->idle_timeout));
+		wake_lock(&conn->idle_lock);
+	}
 }
 
 static inline void hci_conn_stop_rssi_timer(struct hci_conn *conn)
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 395a95c..9e545f3 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2556,6 +2556,9 @@
 			else
 				conn->power_save = 0;
 		}
+		if (conn->mode == HCI_CM_SNIFF)
+			if (wake_lock_active(&conn->idle_lock))
+				wake_unlock(&conn->idle_lock);
 
 		if (test_and_clear_bit(HCI_CONN_SCO_SETUP_PEND, &conn->pend))
 			hci_sco_setup(conn, ev->status);