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, 1 insertions, 9 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 20dc2add27ba..15b36e2efa85 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -410,20 +410,12 @@ static int acm_submit_read_urbs(struct acm *acm, gfp_t mem_flags)
 
 static void acm_process_read_urb(struct acm *acm, struct urb *urb)
 {
-        struct tty_struct *tty;
-
         if (!urb->actual_length)
                 return;
 
-        tty = tty_port_tty_get(&acm->port);
-        if (!tty)
-                return;
-
         tty_insert_flip_string(&acm->port, urb->transfer_buffer,
                         urb->actual_length);
-        tty_flip_buffer_push(tty);
-
-        tty_kref_put(tty);
+        tty_flip_buffer_push(&acm->port);
 }
 
 static void acm_read_bulk_callback(struct urb *urb)