usb_serial: API all change

USB serial likes to use port->tty back pointers for the real work it does and
to do so without any actual locking. Unfortunately when you consider hangup
events, hangup/parallel reopen or even worse hangup followed by parallel close
events the tty->port and port->tty pointers are not guaranteed to be the same
as port->tty is the active tty while tty->port is the port the tty may or
may not still be attached to.

So rework the entire API to pass the tty struct. For console cases we need
to pass both for now. This shows up multiple drivers that immediately crash
with USB console some of which have been fixed in the process.

Longer term we need a proper tty as console abstraction

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index 1f7c86bd8297..f61e3ca64305 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -232,7 +232,8 @@ error:	kfree(priv);
 }
 
 /* open this device, set default parameters */
-static int ch341_open(struct usb_serial_port *port, struct file *filp)
+static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
+                                struct file *filp)
 {
         struct usb_serial *serial = port->serial;
         struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
@@ -256,7 +257,7 @@ static int ch341_open(struct usb_serial_port *port, struct file *filp)
         if (r)
                 goto out;
 
-        r = usb_serial_generic_open(port, filp);
+        r = usb_serial_generic_open(tty, port, filp);
 
 out:    return r;
 }
@@ -264,11 +265,10 @@ out:	return r;
 /* Old_termios contains the original termios settings and
  * tty->termios contains the new setting to be used.
  */
-static void ch341_set_termios(struct usb_serial_port *port,
-                              struct ktermios *old_termios)
+static void ch341_set_termios(struct tty_struct *tty,
+                struct usb_serial_port *port, struct ktermios *old_termios)
 {
         struct ch341_private *priv = usb_get_serial_port_data(port);
-        struct tty_struct *tty = port->tty;
         unsigned baud_rate;
 
         dbg("ch341_set_termios()");