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>
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 9127c54..130c8cf 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -236,12 +236,12 @@
spin_lock_irqsave(&port->lock, flags);
port->count = 0;
- port->flags &= ~ASYNC_NORMAL_ACTIVE;
tty = port->tty;
if (tty)
set_bit(TTY_IO_ERROR, &tty->flags);
port->tty = NULL;
spin_unlock_irqrestore(&port->lock, flags);
+ tty_port_set_active(port, 0);
tty_port_shutdown(port, tty);
tty_kref_put(tty);
wake_up_interruptible(&port->open_wait);
@@ -365,14 +365,14 @@
/* if non-blocking mode is set we can pass directly to open unless
the port has just hung up or is in another error state */
if (tty_io_error(tty)) {
- port->flags |= ASYNC_NORMAL_ACTIVE;
+ tty_port_set_active(port, 1);
return 0;
}
if (filp->f_flags & O_NONBLOCK) {
/* Indicate we are open */
if (C_BAUD(tty))
tty_port_raise_dtr_rts(port);
- port->flags |= ASYNC_NORMAL_ACTIVE;
+ tty_port_set_active(port, 1);
return 0;
}
@@ -430,9 +430,9 @@
if (!tty_hung_up_p(filp))
port->count++;
port->blocked_open--;
- if (retval == 0)
- port->flags |= ASYNC_NORMAL_ACTIVE;
spin_unlock_irqrestore(&port->lock, flags);
+ if (retval == 0)
+ tty_port_set_active(port, 1);
return retval;
}
EXPORT_SYMBOL(tty_port_block_til_ready);
@@ -514,8 +514,8 @@
spin_lock_irqsave(&port->lock, flags);
wake_up_interruptible(&port->open_wait);
}
- port->flags &= ~ASYNC_NORMAL_ACTIVE;
spin_unlock_irqrestore(&port->lock, flags);
+ tty_port_set_active(port, 0);
}
EXPORT_SYMBOL(tty_port_close_end);