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/include/linux/tty.h b/include/linux/tty.h
index 989d755b..dbeeb86 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -571,6 +571,18 @@
clear_bit(TTY_PORT_CTS_FLOW, &port->iflags);
}
+static inline bool tty_port_active(struct tty_port *port)
+{
+ return test_bit(TTY_PORT_ACTIVE, &port->iflags);
+}
+
+static inline void tty_port_set_active(struct tty_port *port, bool val)
+{
+ if (val)
+ set_bit(TTY_PORT_ACTIVE, &port->iflags);
+ else
+ clear_bit(TTY_PORT_ACTIVE, &port->iflags);
+}
extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);