USB: tty: Prune uses of tty_request_room in the USB layer

We have lots of callers that do not need to do this in the first place.
Remove the calls as they both cost CPU and for big buffers can mess up the
multi-page allocation avoidance.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 8 deletions

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index 773286672ec9..f37476e22684 100644
--- a/drivers/usb/serial/opticon.c
+++ b/drivers/usb/serial/opticon.c
@@ -55,7 +55,6 @@ static void opticon_bulk_callback(struct urb *urb)
         int status = urb->status;
         struct tty_struct *tty;
         int result;
-        int available_room = 0;
         int data_length;
 
         dbg("%s - port %d", __func__, port->number);
@@ -96,13 +95,9 @@ static void opticon_bulk_callback(struct urb *urb)
                         /* real data, send it to the tty layer */
                         tty = tty_port_tty_get(&port->port);
                         if (tty) {
-                                available_room = tty_buffer_request_room(tty,
-                                                                data_length);
-                                if (available_room) {
-                                        tty_insert_flip_string(tty, data,
-                                                               available_room);
-                                        tty_flip_buffer_push(tty);
-                                }
+                                tty_insert_flip_string(tty, data,
+                                                               data_length);
+                                tty_flip_buffer_push(tty);
                                 tty_kref_put(tty);
                         }
                 } else {