tty: Use spin_lock_irq() for ctrl_lock when interrupts enabled

Interrupts are enabled in the n_tty_read() loop, ioctl(TIOCPKT)
and pty driver flush_buffer() routine; no need to save and restore
local interrupt state.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 89c4cee253e3..d521058ee55a 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2128,7 +2128,6 @@ 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 +2173,10 @@ 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--;