tty: Add a full port_close function
Now we are extracting out methods for shutdown and the like we can add a
proper tty_port_close method that knows all the innards of the tty closing
process and hides the lot from the caller.
At some point in the future this will be paired with a similar open()
helper and the drivers can stick to hardware management.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 9769b11..549bd0f 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -96,6 +96,14 @@
}
EXPORT_SYMBOL(tty_port_tty_set);
+static void tty_port_shutdown(struct tty_port *port)
+{
+ if (port->ops->shutdown &&
+ test_and_clear_bit(ASYNC_INITIALIZED, &port->flags))
+ port->ops->shutdown(port);
+
+}
+
/**
* tty_port_hangup - hangup helper
* @port: tty port
@@ -116,6 +124,7 @@
port->tty = NULL;
spin_unlock_irqrestore(&port->lock, flags);
wake_up_interruptible(&port->open_wait);
+ tty_port_shutdown(port);
}
EXPORT_SYMBOL(tty_port_hangup);
@@ -296,15 +305,17 @@
if (port->count) {
spin_unlock_irqrestore(&port->lock, flags);
+ if (port->ops->drop)
+ port->ops->drop(port);
return 0;
}
- port->flags |= ASYNC_CLOSING;
+ set_bit(ASYNC_CLOSING, &port->flags);
tty->closing = 1;
spin_unlock_irqrestore(&port->lock, flags);
/* Don't block on a stalled port, just pull the chain */
if (tty->flow_stopped)
tty_driver_flush_buffer(tty);
- if (port->flags & ASYNC_INITIALIZED &&
+ if (test_bit(ASYNCB_INITIALIZED, &port->flags) &&
port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
tty_wait_until_sent(tty, port->closing_wait);
if (port->drain_delay) {
@@ -318,6 +329,9 @@
timeout = 2 * HZ;
schedule_timeout_interruptible(timeout);
}
+ /* Don't call port->drop for the last reference. Callers will want
+ to drop the last active reference in ->shutdown() or the tty
+ shutdown path */
return 1;
}
EXPORT_SYMBOL(tty_port_close_start);
@@ -348,3 +362,14 @@
spin_unlock_irqrestore(&port->lock, flags);
}
EXPORT_SYMBOL(tty_port_close_end);
+
+void tty_port_close(struct tty_port *port, struct tty_struct *tty,
+ struct file *filp)
+{
+ if (tty_port_close_start(port, tty, filp) == 0)
+ return;
+ tty_port_shutdown(port);
+ tty_port_close_end(port, tty);
+ tty_port_tty_set(port, NULL);
+}
+EXPORT_SYMBOL(tty_port_close);