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, 6 insertions, 4 deletions

diff --git a/drivers/usb/serial/navman.c b/drivers/usb/serial/navman.c
index 43c8894353bf..d6736531a0fa 100644
--- a/drivers/usb/serial/navman.c
+++ b/drivers/usb/serial/navman.c
@@ -64,7 +64,7 @@ static void navman_read_int_callback(struct urb *urb)
         usb_serial_debug_data(debug, &port->dev, __func__,
                               urb->actual_length, data);
 
-        tty = port->tty;
+        tty = port->port.tty;
         if (tty && urb->actual_length) {
                 tty_buffer_request_room(tty, urb->actual_length);
                 tty_insert_flip_string(tty, data, urb->actual_length);
@@ -79,7 +79,8 @@ exit:
                         __func__, result);
 }
 
-static int navman_open(struct usb_serial_port *port, struct file *filp)
+static int navman_open(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         int result = 0;
 
@@ -96,14 +97,15 @@ static int navman_open(struct usb_serial_port *port, struct file *filp)
         return result;
 }
 
-static void navman_close(struct usb_serial_port *port, struct file *filp)
+static void navman_close(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         dbg("%s - port %d", __func__, port->number);
 
         usb_kill_urb(port->interrupt_in_urb);
 }
 
-static int navman_write(struct usb_serial_port *port,
+static int navman_write(struct tty_struct *tty, struct usb_serial_port *port,
                         const unsigned char *buf, int count)
 {
         dbg("%s - port %d", __func__, port->number);