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, 7 insertions, 12 deletions

diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index 66fb58f427c..3ef8df0ef88 100644
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -2055,18 +2055,13 @@ static void edge_tty_recv(struct device *dev, struct tty_struct *tty,
 {
         int cnt;
 
-        do {
-                cnt = tty_buffer_request_room(tty, length);
-                if (cnt < length) {
-                        dev_err(dev, "%s - dropping data, %d bytes lost\n",
-                                        __func__, length - cnt);
-                        if (cnt == 0)
-                                break;
-                }
-                tty_insert_flip_string(tty, data, cnt);
-                data += cnt;
-                length -= cnt;
-        } while (length > 0);
+        cnt = tty_insert_flip_string(tty, data, length);
+        if (cnt < length) {
+                dev_err(dev, "%s - dropping data, %d bytes lost\n",
+                                __func__, length - cnt);
+        }
+        data += cnt;
+        length -= cnt;
 
         tty_flip_buffer_push(tty);
 }