tty: Replace ASYNC_NORMAL_ACTIVE bit and update atomically

Replace ASYNC_NORMAL_ACTIVE bit in the tty_port::flags field with
TTY_PORT_ACTIVE bit in the tty_port::iflags field. Introduce helpers
tty_port_set_active() and tty_port_active() to abstract atomic bit ops.

Extract state changes from port lock sections, as this usage is
broken and confused; the state transitions are protected by the
tty lock (which mutually excludes parallel open/close/hangup),
and no user tests the active state while holding the port lock.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/tty/serial/crisv10.c b/drivers/tty/serial/crisv10.c
index 546990334815..92c8c628e00e 100644
--- a/drivers/tty/serial/crisv10.c
+++ b/drivers/tty/serial/crisv10.c
@@ -3648,8 +3648,8 @@ rs_close(struct tty_struct *tty, struct file * filp)
                         schedule_timeout_interruptible(info->port.close_delay);
                 wake_up_interruptible(&info->port.open_wait);
         }
-        info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
         local_irq_restore(flags);
+        tty_port_set_active(&info->port, 0);
 
         /* port closed */
 
@@ -3732,7 +3732,7 @@ rs_hangup(struct tty_struct *tty)
         shutdown(info);
         info->event = 0;
         info->port.count = 0;
-        info->port.flags &= ~ASYNC_NORMAL_ACTIVE;
+        tty_port_set_active(&info->port, 0);
         info->port.tty = NULL;
         wake_up_interruptible(&info->port.open_wait);
 }
@@ -3756,7 +3756,7 @@ block_til_ready(struct tty_struct *tty, struct file * filp,
          * then make the check up front and then exit.
          */
         if ((filp->f_flags & O_NONBLOCK) || tty_io_error(tty)) {
-                info->port.flags |= ASYNC_NORMAL_ACTIVE;
+                tty_port_set_active(&info->port, 1);
                 return 0;
         }
 
@@ -3825,7 +3825,7 @@ block_til_ready(struct tty_struct *tty, struct file * filp,
 #endif
         if (retval)
                 return retval;
-        info->port.flags |= ASYNC_NORMAL_ACTIVE;
+        tty_port_set_active(&info->port, 1);
         return 0;
 }