tty: serial: fsl_lpuart: count tty buffer overruns

Added support for counting the tty buffer overruns in fsl_lpuart driver
like other uart drivers.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20220111085130.5817-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index ce3e2614468983d60b3c96f24dc1a2f284c107ba..7d90c5a530ee1a4c68c34b41b16e9b38f00fd897 100644 (file)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -931,7 +931,8 @@ static void lpuart_rxint(struct lpuart_port *sport)
                        sport->port.sysrq = 0;
                }
 
-               tty_insert_flip_char(port, rx, flg);
+               if (tty_insert_flip_char(port, rx, flg) == 0)
+                       sport->port.icount.buf_overrun++;
        }
 
 out:
@@ -1024,7 +1025,8 @@ static void lpuart32_rxint(struct lpuart_port *sport)
                                flg = TTY_OVERRUN;
                }
 
-               tty_insert_flip_char(port, rx, flg);
+               if (tty_insert_flip_char(port, rx, flg) == 0)
+                       sport->port.icount.buf_overrun++;
        }
 
 out:
@@ -1116,7 +1118,7 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
        struct dma_chan *chan = sport->dma_rx_chan;
        struct circ_buf *ring = &sport->rx_ring;
        unsigned long flags;
-       int count = 0;
+       int count = 0, copied;
 
        if (lpuart_is_32(sport)) {
                unsigned long sr = lpuart32_read(&sport->port, UARTSTAT);
@@ -1218,20 +1220,24 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
        if (ring->head < ring->tail) {
                count = sport->rx_sgl.length - ring->tail;
 
-               tty_insert_flip_string(port, ring->buf + ring->tail, count);
+               copied = tty_insert_flip_string(port, ring->buf + ring->tail, count);
+               if (copied != count)
+                       sport->port.icount.buf_overrun++;
                ring->tail = 0;
-               sport->port.icount.rx += count;
+               sport->port.icount.rx += copied;
        }
 
        /* Finally we read data from tail to head */
        if (ring->tail < ring->head) {
                count = ring->head - ring->tail;
-               tty_insert_flip_string(port, ring->buf + ring->tail, count);
+               copied = tty_insert_flip_string(port, ring->buf + ring->tail, count);
+               if (copied != count)
+                       sport->port.icount.buf_overrun++;
                /* Wrap ring->head if needed */
                if (ring->head >= sport->rx_sgl.length)
                        ring->head = 0;
                ring->tail = ring->head;
-               sport->port.icount.rx += count;
+               sport->port.icount.rx += copied;
        }
 
 exit: