1 files changed, 14 insertions, 8 deletions

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 6129fe515932..10256fa04b40 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -681,7 +681,7 @@ static unsigned int serial_omap_get_mctrl(struct uart_port *port)
 static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
         struct uart_omap_port *up = to_uart_omap_port(port);
-        unsigned char mcr = 0, old_mcr;
+        unsigned char mcr = 0, old_mcr, lcr;
 
         dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
         if (mctrl & TIOCM_RTS)
@@ -701,6 +701,17 @@ static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
                      UART_MCR_DTR | UART_MCR_RTS);
         up->mcr = old_mcr | mcr;
         serial_out(up, UART_MCR, up->mcr);
+
+        /* Turn off autoRTS if RTS is lowered; restore autoRTS if RTS raised */
+        lcr = serial_in(up, UART_LCR);
+        serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+        if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+                up->efr |= UART_EFR_RTS;
+        else
+                up->efr &= UART_EFR_RTS;
+        serial_out(up, UART_EFR, up->efr);
+        serial_out(up, UART_LCR, lcr);
+
         pm_runtime_mark_last_busy(up->dev);
         pm_runtime_put_autosuspend(up->dev);
 }
@@ -756,8 +767,6 @@ static int serial_omap_startup(struct uart_port *port)
          * (they will be reenabled in set_termios())
          */
         serial_omap_clear_fifos(up);
-        /* For Hardware flow control */
-        serial_out(up, UART_MCR, UART_MCR_RTS);
 
         /*
          * Clear the interrupt registers.
@@ -1056,12 +1065,9 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
         up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
 
         if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
-                /* Enable AUTORTS and AUTOCTS */
+                /* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
                 up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
-                up->efr |= UART_EFR_CTS | UART_EFR_RTS;
-
-                /* Ensure MCR RTS is asserted */
-                up->mcr |= UART_MCR_RTS;
+                up->efr |= UART_EFR_CTS;
         } else {
                 /* Disable AUTORTS and AUTOCTS */
                 up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);