Revert "Bluetooth: Voting UART clocks in non atomic context."

This reverts commit 2fed6b6f759ebeb4a678f399a192815c5ab136e5.
Bluetooth sleep mechanism is not stable with the new design.

Change-Id: I9fa7e3af5b2668764f5fb335d93a54451568f857
Signed-off-by: Ram Mohan Korukonda <rkorukon@codeaurora.org>
diff --git a/drivers/bluetooth/hci_ibs.c b/drivers/bluetooth/hci_ibs.c
index 6845020..fb084f5 100644
--- a/drivers/bluetooth/hci_ibs.c
+++ b/drivers/bluetooth/hci_ibs.c
@@ -37,9 +37,7 @@
 #include <linux/fcntl.h>
 #include <linux/interrupt.h>
 #include <linux/ptrace.h>
-#include <linux/ftrace.h>
 #include <linux/poll.h>
-#include <linux/workqueue.h>
 
 #include <linux/slab.h>
 #include <linux/tty.h>
@@ -94,15 +92,6 @@
 	HCI_IBS_RX_VOTE_CLOCK_OFF,
 };
 
-/* HCI_IBS state for the WorkQueue */
-enum hci_ibs_wq_state_e {
-	HCI_IBS_WQ_INIT_STATE = 0,
-	HCI_IBS_WQ_TX_VOTE_OFF,
-	HCI_IBS_WQ_RX_VOTE_OFF,
-	HCI_IBS_WQ_AWAKE_RX,
-	HCI_IBS_WQ_AWAKE_DEVICE,
-};
-
 static unsigned long wake_retrans = 1;
 static unsigned long tx_idle_delay = (HZ * 2);
 
@@ -123,11 +112,6 @@
 	unsigned long rx_vote;		/* clock must be on for RX */
 	struct	timer_list tx_idle_timer;
 	struct	timer_list wake_retrans_timer;
-	struct	workqueue_struct *workqueue;
-	struct	work_struct ws_ibs;
-	unsigned long ibs_wq_state;
-	void *ibs_hu; /* keeps the hci_uart pointer for reference */
-
 	/* debug */
 	unsigned long ibs_sent_wacks;
 	unsigned long ibs_sent_slps;
@@ -258,56 +242,6 @@
 	return err;
 }
 
-static void ibs_wq(struct work_struct *work)
-{
-	unsigned long flags = 0;
-	struct ibs_struct *ibs = container_of(work, struct ibs_struct,
-						ws_ibs);
-	struct hci_uart *hu = (struct hci_uart *)ibs->ibs_hu;
-
-	BT_DBG("hu %p, ibs_wq state: %lu\n", hu, ibs->ibs_wq_state);
-
-	/* lock hci_ibs state */
-	spin_lock_irqsave(&ibs->hci_ibs_lock, flags);
-
-	switch (ibs->ibs_wq_state) {
-	case HCI_IBS_WQ_AWAKE_DEVICE:
-		/* Vote for serial clock */
-		ibs_msm_serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_ON, hu);
-
-		/* send wake indication to device */
-		if (send_hci_ibs_cmd(HCI_IBS_WAKE_IND, hu) < 0)
-			BT_ERR("cannot send WAKE to device");
-
-		ibs->ibs_sent_wakes++; /* debug */
-
-		/* start retransmit timer */
-		mod_timer(&ibs->wake_retrans_timer, jiffies + wake_retrans);
-		break;
-	case HCI_IBS_WQ_AWAKE_RX:
-		ibs_msm_serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_ON, hu);
-		ibs->rx_ibs_state = HCI_IBS_RX_AWAKE;
-
-		if (send_hci_ibs_cmd(HCI_IBS_WAKE_ACK, hu) < 0)
-			BT_ERR("cannot acknowledge device wake up");
-
-		ibs->ibs_sent_wacks++; /* debug */
-		/* actually send the packets */
-		hci_uart_tx_wakeup(hu);
-		break;
-	case HCI_IBS_WQ_RX_VOTE_OFF:
-		ibs_msm_serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_OFF, hu);
-		break;
-	case HCI_IBS_WQ_TX_VOTE_OFF:
-		ibs_msm_serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_OFF, hu);
-		break;
-	default:
-		BT_DBG("Invalid state in ibs workqueue");
-		break;
-	}
-	spin_unlock_irqrestore(&ibs->hci_ibs_lock, flags);
-}
-
 static void hci_ibs_tx_idle_timeout(unsigned long arg)
 {
 	struct hci_uart *hu = (struct hci_uart *) arg;
@@ -348,9 +282,7 @@
 
 	spin_lock_irqsave_nested(&ibs->hci_ibs_lock,
 					flags, SINGLE_DEPTH_NESTING);
-	/* vote off tx clock */
-	ibs->ibs_wq_state = HCI_IBS_WQ_TX_VOTE_OFF;
-	queue_work(ibs->workqueue, &ibs->ws_ibs);
+	ibs_msm_serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_OFF, hu);
 out:
 	spin_unlock_irqrestore(&ibs->hci_ibs_lock, flags);
 }
@@ -404,16 +336,6 @@
 	skb_queue_head_init(&ibs->txq);
 	skb_queue_head_init(&ibs->tx_wait_q);
 	spin_lock_init(&ibs->hci_ibs_lock);
-	ibs->workqueue = create_singlethread_workqueue("ibs_wq");
-	if (!ibs->workqueue) {
-		BT_ERR("IBS Workqueue not initialized properly");
-		kfree(ibs);
-		return -ENOMEM;
-	}
-
-	INIT_WORK(&ibs->ws_ibs, ibs_wq);
-	ibs->ibs_hu = (void *)hu;
-	ibs->ibs_wq_state = HCI_IBS_WQ_INIT_STATE;
 
 	/* Assume we start with both sides asleep -- extra wakes OK */
 	ibs->tx_ibs_state = HCI_IBS_TX_ASLEEP;
@@ -510,8 +432,6 @@
 	skb_queue_purge(&ibs->txq);
 	del_timer(&ibs->tx_idle_timer);
 	del_timer(&ibs->wake_retrans_timer);
-	destroy_workqueue(ibs->workqueue);
-	ibs->ibs_hu = NULL;
 
 	kfree_skb(ibs->rx_skb);
 
@@ -543,11 +463,9 @@
 		/* Make sure clock is on - we may have turned clock off since
 		 * receiving the wake up indicator
 		 */
-		/* awake rx clock */
-		ibs->ibs_wq_state = HCI_IBS_WQ_AWAKE_RX;
-		queue_work(ibs->workqueue, &ibs->ws_ibs);
-		spin_unlock_irqrestore(&ibs->hci_ibs_lock, flags);
-		return;
+		ibs_msm_serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_ON, hu);
+		ibs->rx_ibs_state = HCI_IBS_RX_AWAKE;
+		/* deliberate fall-through */
 	case HCI_IBS_RX_AWAKE:
 		/* Always acknowledge device wake up,
 		 * sending IBS message doesn't count as TX ON.
@@ -592,9 +510,7 @@
 	case HCI_IBS_RX_AWAKE:
 		/* update state */
 		ibs->rx_ibs_state = HCI_IBS_RX_ASLEEP;
-		/* vote off rx clock under workqueue */
-		ibs->ibs_wq_state = HCI_IBS_WQ_RX_VOTE_OFF;
-		queue_work(ibs->workqueue, &ibs->ws_ibs);
+		ibs_msm_serial_clock_vote(HCI_IBS_RX_VOTE_CLOCK_OFF, hu);
 		break;
 	case HCI_IBS_RX_ASLEEP:
 		/* deliberate fall-through */
@@ -679,12 +595,20 @@
 
 	case HCI_IBS_TX_ASLEEP:
 		BT_DBG("device asleep, waking up and queueing packet");
+		ibs_msm_serial_clock_vote(HCI_IBS_TX_VOTE_CLOCK_ON, hu);
 		/* save packet for later */
 		skb_queue_tail(&ibs->tx_wait_q, skb);
+		/* awake device */
+		if (send_hci_ibs_cmd(HCI_IBS_WAKE_IND, hu) < 0) {
+			BT_ERR("cannot send WAKE to device");
+			break;
+		}
+		ibs->ibs_sent_wakes++; /* debug */
+
+		/* start retransmit timer */
+		mod_timer(&ibs->wake_retrans_timer, jiffies + wake_retrans);
+
 		ibs->tx_ibs_state = HCI_IBS_TX_WAKING;
-		/* schedule a work queue to wake up device */
-		ibs->ibs_wq_state = HCI_IBS_WQ_AWAKE_DEVICE;
-		queue_work(ibs->workqueue, &ibs->ws_ibs);
 		break;
 
 	case HCI_IBS_TX_WAKING: