pch_uart: fix auto flow control miss-setting issue

Currently, auto-flow control setting processing is not set correctly.
This patch fixes the issue.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 6 deletions

diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 189886122516..0c95051fa0a4 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -218,6 +218,7 @@ struct eg20t_port {
         struct pch_uart_buffer rxbuf;
         unsigned int dmsr;
         unsigned int fcr;
+        unsigned int mcr;
         unsigned int use_dma;
         unsigned int use_dma_flag;
         struct dma_async_tx_descriptor  *desc_tx;
@@ -1007,7 +1008,6 @@ static unsigned int pch_uart_get_mctrl(struct uart_port *port)
 static void pch_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
         u32 mcr = 0;
-        unsigned int dat;
         struct eg20t_port *priv = container_of(port, struct eg20t_port, port);
 
         if (mctrl & TIOCM_DTR)
@@ -1017,11 +1017,11 @@ static void pch_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
         if (mctrl & TIOCM_LOOP)
                 mcr |= UART_MCR_LOOP;
 
-        if (mctrl) {
-                dat = pch_uart_get_mctrl(port);
-                dat |= mcr;
-                iowrite8(dat, priv->membase + UART_MCR);
-        }
+        if (priv->mcr & UART_MCR_AFE)
+                mcr |= UART_MCR_AFE;
+
+        if (mctrl)
+                iowrite8(mcr, priv->membase + UART_MCR);
 }
 
 static void pch_uart_stop_tx(struct uart_port *port)
@@ -1215,6 +1215,13 @@ static void pch_uart_set_termios(struct uart_port *port,
         } else {
                 parity = PCH_UART_HAL_PARITY_NONE;
         }
+
+        /* Only UART0 has auto hardware flow function */
+        if ((termios->c_cflag & CRTSCTS) && (priv->fifo_size == 256))
+                priv->mcr |= UART_MCR_AFE;
+        else
+                priv->mcr &= ~UART_MCR_AFE;
+
         termios->c_cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
 
         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);