[PATCH -next 4/9] tty: Use spin_lock_irq() for ctrl_lock when interrupts enabled

From: Peter Hurley
Date: Thu Oct 16 2014 - 15:34:34 EST


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@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/n_tty.c | 5 ++---
drivers/tty/pty.c | 10 ++++------
2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index f44f1ba..53cdfbe 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--;
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 3943747..29b5eeb 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -178,13 +178,12 @@ static int pty_get_lock(struct tty_struct *tty, int __user *arg)
/* Set the packet mode on a pty */
static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
{
- unsigned long flags;
int pktmode;

if (get_user(pktmode, arg))
return -EFAULT;

- spin_lock_irqsave(&tty->ctrl_lock, flags);
+ spin_lock_irq(&tty->ctrl_lock);
if (pktmode) {
if (!tty->packet) {
tty->packet = 1;
@@ -192,7 +191,7 @@ static int pty_set_pktmode(struct tty_struct *tty, int __user *arg)
}
} else
tty->packet = 0;
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ spin_unlock_irq(&tty->ctrl_lock);

return 0;
}
@@ -221,16 +220,15 @@ static int pty_signal(struct tty_struct *tty, int sig)
static void pty_flush_buffer(struct tty_struct *tty)
{
struct tty_struct *to = tty->link;
- unsigned long flags;

if (!to)
return;
/* tty_buffer_flush(to); FIXME */
if (to->packet) {
- spin_lock_irqsave(&tty->ctrl_lock, flags);
+ spin_lock_irq(&tty->ctrl_lock);
tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
wake_up_interruptible(&to->read_wait);
- spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+ spin_unlock_irq(&tty->ctrl_lock);
}
}

--
2.1.1

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