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, 9 insertions, 9 deletions

diff --git a/drivers/usb/serial/spcp8x5.c b/drivers/usb/serial/spcp8x5.c
index 04e373152724..91ff8e3bddbd 100644
--- a/drivers/usb/serial/spcp8x5.c
+++ b/drivers/usb/serial/spcp8x5.c
@@ -462,7 +462,6 @@ static void spcp8x5_process_read_urb(struct urb *urb)
 {
         struct usb_serial_port *port = urb->context;
         struct spcp8x5_private *priv = usb_get_serial_port_data(port);
-        struct tty_struct *tty;
         unsigned char *data = urb->transfer_buffer;
         unsigned long flags;
         u8 status;
@@ -481,9 +480,6 @@ static void spcp8x5_process_read_urb(struct urb *urb)
         if (!urb->actual_length)
                 return;
 
-        tty = tty_port_tty_get(&port->port);
-        if (!tty)
-                return;
 
         if (status & UART_STATE_TRANSIENT_MASK) {
                 /* break takes precedence over parity, which takes precedence
@@ -500,15 +496,19 @@ static void spcp8x5_process_read_urb(struct urb *urb)
                 if (status & UART_OVERRUN_ERROR)
                         tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
 
-                if (status & UART_DCD)
-                        usb_serial_handle_dcd_change(port, tty,
-                                   priv->line_status & MSR_STATUS_LINE_DCD);
+                if (status & UART_DCD) {
+                        struct tty_struct *tty = tty_port_tty_get(&port->port);
+                        if (tty) {
+                                usb_serial_handle_dcd_change(port, tty,
+                                       priv->line_status & MSR_STATUS_LINE_DCD);
+                                tty_kref_put(tty);
+                        }
+                }
         }
 
         tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
                                                         urb->actual_length);
-        tty_flip_buffer_push(tty);
-        tty_kref_put(tty);
+        tty_flip_buffer_push(&port->port);
 }
 
 static int spcp8x5_wait_modem_info(struct usb_serial_port *port,