From dcbcfb06b0a93443807e10657844c27304baec82 Mon Sep 17 00:00:00 2001
From: Jiri Slaby <jslaby@suse.cz>
Date: Mon, 2 Apr 2012 13:54:30 +0200
Subject: [PATCH] --- yaml --- r: 304159 b: refs/heads/master c:
 daea440215ae86bf9fdfe82420710ae749eb73c7 h: refs/heads/master i:   304157:
 5ea0fc7a12da6f0e1983fd71124c4e2663abeebe   304155:
 45698f4621b4ada8b11ab7f7c0008fbefeb94a10   304151:
 1ecb0a32d2c2f8dc2b7fe964f79a7de6a0e818a5   304143:
 90c8d0a9e48932012d2877740a2c0164d788b037   304127:
 50942c5596af96b4a64e1f523832cf4dddc2cdd8 v: v3

---
 [refs]                       |  2 +-
 trunk/drivers/tty/hvc/hvsi.c | 35 +++++++++++++++++++++--------------
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/[refs] b/[refs]
index d7f0245f16a3..374f50a39997 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 28c0447d743ba94562f981bf09dda61bc4cc6f3b
+refs/heads/master: daea440215ae86bf9fdfe82420710ae749eb73c7
diff --git a/trunk/drivers/tty/hvc/hvsi.c b/trunk/drivers/tty/hvc/hvsi.c
index 68b729b8d1eb..6f5bc49c441f 100644
--- a/trunk/drivers/tty/hvc/hvsi.c
+++ b/trunk/drivers/tty/hvc/hvsi.c
@@ -76,7 +76,6 @@ struct hvsi_struct {
 	wait_queue_head_t stateq; /* woken when HVSI state changes */
 	spinlock_t lock;
 	int index;
-	struct tty_struct *tty;
 	uint8_t throttle_buf[128];
 	uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
 	/* inbuf is for packet reassembly. leave a little room for leftovers. */
@@ -492,14 +491,17 @@ static irqreturn_t hvsi_interrupt(int irq, void *arg)
 {
 	struct hvsi_struct *hp = (struct hvsi_struct *)arg;
 	struct hvsi_struct *handshake;
+	struct tty_struct *tty;
 	unsigned long flags;
 	int again = 1;
 
 	pr_debug("%s\n", __func__);
 
+	tty = tty_port_tty_get(&hp->port);
+
 	while (again) {
 		spin_lock_irqsave(&hp->lock, flags);
-		again = hvsi_load_chunk(hp, hp->tty, &handshake);
+		again = hvsi_load_chunk(hp, tty, &handshake);
 		spin_unlock_irqrestore(&hp->lock, flags);
 
 		if (handshake) {
@@ -509,15 +511,16 @@ static irqreturn_t hvsi_interrupt(int irq, void *arg)
 	}
 
 	spin_lock_irqsave(&hp->lock, flags);
-	if (hp->tty && hp->n_throttle
-			&& (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
-		/* we weren't hung up and we weren't throttled, so we can deliver the
-		 * rest now */
-		hvsi_send_overflow(hp, hp->tty);
-		tty_flip_buffer_push(hp->tty);
+	if (tty && hp->n_throttle && !test_bit(TTY_THROTTLED, &tty->flags)) {
+		/* we weren't hung up and we weren't throttled, so we can
+		 * deliver the rest now */
+		hvsi_send_overflow(hp, tty);
+		tty_flip_buffer_push(tty);
 	}
 	spin_unlock_irqrestore(&hp->lock, flags);
 
+	tty_kref_put(tty);
+
 	return IRQ_HANDLED;
 }
 
@@ -724,8 +727,8 @@ static int hvsi_open(struct tty_struct *tty, struct file *filp)
 	if (hp->state == HVSI_FSP_DIED)
 		return -EIO;
 
+	tty_port_tty_set(&hp->port, tty);
 	spin_lock_irqsave(&hp->lock, flags);
-	hp->tty = tty;
 	hp->port.count++;
 	atomic_set(&hp->seqno, 0);
 	h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
@@ -784,7 +787,7 @@ static void hvsi_close(struct tty_struct *tty, struct file *filp)
 	spin_lock_irqsave(&hp->lock, flags);
 
 	if (--hp->port.count == 0) {
-		hp->tty = NULL;
+		tty_port_tty_set(&hp->port, NULL);
 		hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
 
 		/* only close down connection if it is not the console */
@@ -830,12 +833,11 @@ static void hvsi_hangup(struct tty_struct *tty)
 
 	pr_debug("%s\n", __func__);
 
-	spin_lock_irqsave(&hp->lock, flags);
+	tty_port_tty_set(&hp->port, NULL);
 
+	spin_lock_irqsave(&hp->lock, flags);
 	hp->port.count = 0;
 	hp->n_outbuf = 0;
-	hp->tty = NULL;
-
 	spin_unlock_irqrestore(&hp->lock, flags);
 }
 
@@ -863,6 +865,7 @@ static void hvsi_write_worker(struct work_struct *work)
 {
 	struct hvsi_struct *hp =
 		container_of(work, struct hvsi_struct, writer.work);
+	struct tty_struct *tty;
 	unsigned long flags;
 #ifdef DEBUG
 	static long start_j = 0;
@@ -896,7 +899,11 @@ static void hvsi_write_worker(struct work_struct *work)
 		start_j = 0;
 #endif /* DEBUG */
 		wake_up_all(&hp->emptyq);
-		tty_wakeup(hp->tty);
+		tty = tty_port_tty_get(&hp->port);
+		if (tty) {
+			tty_wakeup(tty);
+			tty_kref_put(tty);
+		}
 	}
 
 out: