Merge tag 'tty-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the big tty/serial driver update for 3.19-rc1.

  There are a number of TTY core changes/fixes in here from Peter Hurley
  that have all been teted in linux-next for a long time now.  There are
  also the normal serial driver updates as well, full details in the
  changelog below"

* tag 'tty-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (219 commits)
  serial: pxa: hold port.lock when reporting modem line changes
  tty-hvsi_lib: Deletion of an unnecessary check before the function call "tty_kref_put"
  tty: Deletion of unnecessary checks before two function calls
  n_tty: Fix read_buf race condition, increment read_head after pushing data
  serial: of-serial: add PM suspend/resume support
  Revert "serial: of-serial: add PM suspend/resume support"
  Revert "serial: of-serial: fix up PM ops on no_console_suspend and port type"
  serial: 8250: don't attempt a trylock if in sysrq
  serial: core: Add big-endian iotype
  serial: samsung: use port->fifosize instead of hardcoded values
  serial: samsung: prefer to use fifosize from driver data
  serial: samsung: fix style problems
  serial: samsung: wait for transfer completion before clock disable
  serial: icom: fix error return code
  serial: tegra: clean up tty-flag assignments
  serial: Fix io address assign flow with Fintek PCI-to-UART Product
  serial: mxs-auart: fix tx_empty against shift register
  serial: mxs-auart: fix gpio change detection on interrupt
  serial: mxs-auart: Fix mxs_auart_set_ldisc()
  serial: 8250_dw: Use 64-bit access for OCTEON.
  ...

1 files changed, 37 insertions, 44 deletions

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 26f097f60b10..d2b496750d59 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -321,7 +321,8 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
 
 static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata)
 {
-	*read_buf_addr(ldata, ldata->read_head++) = c;
+	*read_buf_addr(ldata, ldata->read_head) = c;
+	ldata->read_head++;
 }
 
 /**
@@ -351,13 +352,13 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	if (tty->link->packet) {
+		spin_lock_irqsave(&tty->ctrl_lock, flags);
 		tty->ctrl_status |= TIOCPKT_FLUSHREAD;
+		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 		if (waitqueue_active(&tty->link->read_wait))
 			wake_up_interruptible(&tty->link->read_wait);
 	}
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 }
 
 /**
@@ -2128,7 +2129,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 	int minimum, time;
 	ssize_t retval = 0;
 	long timeout;
-	unsigned long flags;
 	int packet;
 
 	c = job_control(tty, file);
@@ -2174,10 +2174,10 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 			unsigned char cs;
 			if (b != buf)
 				break;
-			spin_lock_irqsave(&tty->link->ctrl_lock, flags);
+			spin_lock_irq(&tty->link->ctrl_lock);
 			cs = tty->link->ctrl_status;
 			tty->link->ctrl_status = 0;
-			spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
+			spin_unlock_irq(&tty->link->ctrl_lock);
 			if (tty_put_user(tty, cs, b++)) {
 				retval = -EFAULT;
 				b--;
@@ -2193,45 +2193,29 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 
 		if (!input_available_p(tty, 0)) {
 			if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
-				up_read(&tty->termios_rwsem);
-				tty_flush_to_ldisc(tty);
-				down_read(&tty->termios_rwsem);
-				if (!input_available_p(tty, 0)) {
-					retval = -EIO;
-					break;
-				}
-			} else {
-				if (tty_hung_up_p(file))
-					break;
-				if (!timeout)
-					break;
-				if (file->f_flags & O_NONBLOCK) {
-					retval = -EAGAIN;
-					break;
-				}
-				if (signal_pending(current)) {
-					retval = -ERESTARTSYS;
-					break;
-				}
-				n_tty_set_room(tty);
-				up_read(&tty->termios_rwsem);
-
-				timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
-						     timeout);
-
-				down_read(&tty->termios_rwsem);
-				continue;
+				retval = -EIO;
+				break;
 			}
-		}
-
-		/* Deal with packet mode. */
-		if (packet && b == buf) {
-			if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
-				retval = -EFAULT;
-				b--;
+			if (tty_hung_up_p(file))
+				break;
+			if (!timeout)
+				break;
+			if (file->f_flags & O_NONBLOCK) {
+				retval = -EAGAIN;
 				break;
 			}
-			nr--;
+			if (signal_pending(current)) {
+				retval = -ERESTARTSYS;
+				break;
+			}
+			n_tty_set_room(tty);
+			up_read(&tty->termios_rwsem);
+
+			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
+					     timeout);
+
+			down_read(&tty->termios_rwsem);
+			continue;
 		}
 
 		if (ldata->icanon && !L_EXTPROC(tty)) {
@@ -2243,8 +2227,17 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 				break;
 		} else {
 			int uncopied;
-			/* The copy function takes the read lock and handles
-			   locking internally for this case */
+
+			/* Deal with packet mode. */
+			if (packet && b == buf) {
+				if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
+					retval = -EFAULT;
+					b--;
+					break;
+				}
+				nr--;
+			}
+
 			uncopied = copy_from_read_buf(tty, &b, &nr);
 			uncopied += copy_from_read_buf(tty, &b, &nr);
 			if (uncopied) {