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, 3 insertions, 10 deletions

diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c
index ad12e9e2c7ee..21cd7bf2a8cc 100644
--- a/drivers/usb/serial/safe_serial.c
+++ b/drivers/usb/serial/safe_serial.c
@@ -207,38 +207,31 @@ static void safe_process_read_urb(struct urb *urb)
         unsigned char *data = urb->transfer_buffer;
         unsigned char length = urb->actual_length;
         int actual_length;
-        struct tty_struct *tty;
         __u16 fcs;
 
         if (!length)
                 return;
 
-        tty = tty_port_tty_get(&port->port);
-        if (!tty)
-                return;
-
         if (!safe)
                 goto out;
 
         fcs = fcs_compute10(data, length, CRC10_INITFCS);
         if (fcs) {
                 dev_err(&port->dev, "%s - bad CRC %x\n", __func__, fcs);
-                goto err;
+                return;
         }
 
         actual_length = data[length - 2] >> 2;
         if (actual_length > (length - 2)) {
                 dev_err(&port->dev, "%s - inconsistent lengths %d:%d\n",
                                 __func__, actual_length, length);
-                goto err;
+                return;
         }
         dev_info(&urb->dev->dev, "%s - actual: %d\n", __func__, actual_length);
         length = actual_length;
 out:
         tty_insert_flip_string(&port->port, data, length);
-        tty_flip_buffer_push(tty);
-err:
-        tty_kref_put(tty);
+        tty_flip_buffer_push(&port->port);
 }
 
 static int safe_prepare_write_buffer(struct usb_serial_port *port,