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>
diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index 66fb58f..3ef8df0 100644
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -2055,18 +2055,13 @@
{
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);
}