USB: ftdi_sio: fix legacy SIO-device header

Length field of header was incorrectly set to available payload space
rather than the actual payload size.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 97f2d9c..050211a 100644 (file)
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1752,10 +1752,10 @@ static int ftdi_prepare_write_buffer(struct usb_serial_port *port,
                spin_lock_irqsave(&port->lock, flags);
                for (i = 0; i < size - 1; i += priv->max_packet_size) {
                        len = min_t(int, size - i, priv->max_packet_size) - 1;
-                       buffer[i] = (len << 2) + 1;
                        c = kfifo_out(&port->write_fifo, &buffer[i + 1], len);
                        if (!c)
                                break;
+                       buffer[i] = (c << 2) + 1;
                        count += c + 1;
                }
                spin_unlock_irqrestore(&port->lock, flags);