serial: omap_8250: Fix RTS handling, part B

Because the OMAP3 UART ignores MCR[1] (RTS) in autoRTS mode, autoRTS
mode must not be enabled unless RTS is set (or port->mctrl & TIOCM_RTS,
which is equivalent).

Fixes premature raising of RTS in omap_8250_set_termios() -- RTS was
raised even before UART mode was selected.
Fixes raise of RTS after port has been shutdown; omap_8250_pm() re-enabled
RTS after omap_8250_shutdown().

Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 227033db214b..7c485eaf7dd1 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -272,7 +272,10 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
         serial_dl_write(up, priv->quot);
 
-        serial_out(up, UART_EFR, priv->efr);
+        if (up->port.mctrl & TIOCM_RTS)
+                serial_out(up, UART_EFR, priv->efr);
+        else
+                serial_out(up, UART_EFR, priv->efr & ~UART_EFR_RTS);
 
         /* Configure flow control */
         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
@@ -468,18 +471,18 @@ static void omap_8250_set_termios(struct uart_port *port,
 static void omap_8250_pm(struct uart_port *port, unsigned int state,
                          unsigned int oldstate)
 {
-        struct uart_8250_port *up =
-                container_of(port, struct uart_8250_port, port);
-        struct omap8250_priv *priv = up->port.private_data;
+        struct uart_8250_port *up = up_to_u8250p(port);
+        u8 efr;
 
         pm_runtime_get_sync(port->dev);
         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-        serial_out(up, UART_EFR, priv->efr | UART_EFR_ECB);
+        efr = serial_in(up, UART_EFR);
+        serial_out(up, UART_EFR, efr | UART_EFR_ECB);
         serial_out(up, UART_LCR, 0);
 
         serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-        serial_out(up, UART_EFR, priv->efr);
+        serial_out(up, UART_EFR, efr);
         serial_out(up, UART_LCR, 0);
 
         pm_runtime_mark_last_busy(port->dev);