TTY: switch tty_flip_buffer_push

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 11 deletions

diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c
index 293b460030cb..a547c91e3c05 100644
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -275,7 +275,6 @@ static void usb_wwan_indat_callback(struct urb *urb)
         int err;
         int endpoint;
         struct usb_serial_port *port;
-        struct tty_struct *tty;
         struct device *dev;
         unsigned char *data = urb->transfer_buffer;
         int status = urb->status;
@@ -288,16 +287,12 @@ static void usb_wwan_indat_callback(struct urb *urb)
                 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
                         __func__, status, endpoint);
         } else {
-                tty = tty_port_tty_get(&port->port);
-                if (tty) {
-                        if (urb->actual_length) {
-                                tty_insert_flip_string(&port->port, data,
-                                                urb->actual_length);
-                                tty_flip_buffer_push(tty);
-                        } else
-                                dev_dbg(dev, "%s: empty read urb received\n", __func__);
-                        tty_kref_put(tty);
-                }
+                if (urb->actual_length) {
+                        tty_insert_flip_string(&port->port, data,
+                                        urb->actual_length);
+                        tty_flip_buffer_push(&port->port);
+                } else
+                        dev_dbg(dev, "%s: empty read urb received\n", __func__);
 
                 /* Resubmit urb so we continue receiving */
                 err = usb_submit_urb(urb, GFP_ATOMIC);