serial: omap: fix software flow control

Software flow control register bits were not defined correctly.

Also clarify the IXON and IXOFF logic to reflect what userspace wants.

Cc: stable@vger.kernel.org
Tested-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/plat-omap/include/plat/omap-serial.h

@@ -42,10 +42,10 @@
 #define OMAP_UART_WER_MOD_WKUP	0X7F
 
 /* Enable XON/XOFF flow control on output */
-#define OMAP_UART_SW_TX		0x04
+#define OMAP_UART_SW_TX		0x8
 
 /* Enable XON/XOFF flow control on input */
-#define OMAP_UART_SW_RX		0x04
+#define OMAP_UART_SW_RX		0x2
 
 #define OMAP_UART_SYSC_RESET	0X07
 #define OMAP_UART_TCR_TRIG	0X0F

drivers/tty/serial/omap-serial.c

@@ -617,19 +617,19 @@ serial_omap_configure_xonxoff
 
 	/*
 	 * IXON Flag:
-	 * Enable XON/XOFF flow control on output.
-	 * Transmit XON1, XOFF1
+	 * Flow control for OMAP.TX
+	 * OMAP.RX should listen for XON/XOFF
 	 */
 	if (termios->c_iflag & IXON)
-		up->efr |= OMAP_UART_SW_TX;
+		up->efr |= OMAP_UART_SW_RX;
 
 	/*
 	 * IXOFF Flag:
-	 * Enable XON/XOFF flow control on input.
-	 * Receiver compares XON1, XOFF1.
+	 * Flow control for OMAP.RX
+	 * OMAP.TX should send XON/XOFF
 	 */
 	if (termios->c_iflag & IXOFF)
-		up->efr |= OMAP_UART_SW_RX;
+		up->efr |= OMAP_UART_SW_TX;
 
 	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);