serial: imx: count tty buffer overruns

As can be seen in function uart_insert_char (serial_core) the element
buf_overrun of struct uart_icount is used to count overruns of
tty-buffer.
Added support for counting of overruns in imx driver analogue to
serial_core.

Signed-off-by: Manfred Schlaegl <manfred.schlaegl@gmx.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index cddf9026a72bc1d7afd25a59701c86fb54f90cce..0628fc4841cae99371b4e7bc8b57b6282ecc476a 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -700,7 +700,8 @@ static irqreturn_t imx_rxint(int irq, void *dev_id)
                if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
                        goto out;
 
-               tty_insert_flip_char(port, rx, flg);
+               if (tty_insert_flip_char(port, rx, flg) == 0)
+                       sport->port.icount.buf_overrun++;
        }
 
 out:
@@ -921,8 +922,13 @@ static void dma_rx_callback(void *data)
        dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
 
        if (count) {
-               if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ))
-                       tty_insert_flip_string(port, sport->rx_buf, count);
+               if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
+                       int bytes = tty_insert_flip_string(port, sport->rx_buf,
+                                       count);
+
+                       if (bytes != count)
+                               sport->port.icount.buf_overrun++;
+               }
                tty_flip_buffer_push(port);
 
                start_rx_dma(sport);