[PATCH v3 5/6] serial: imx: update the stop rx,tx procedures

From: Nandor Han <redacted>

According to "Documentation/serial/driver" both procedures should stop
receiving or sending data. Based on this the procedures should stop the
activity regardless if DMA is enabled or not.

This commit updates both imx_stop_{rx|tx} procedures to stop the
activity and disable the interrupts related to that.

Signed-off-by: Nandor Han <redacted>
Signed-off-by: Romain Perier <redacted>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
---
 drivers/tty/serial/imx.c | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index ed02783..256b128 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c

@@ -388,15 +388,14 @@ static void imx_stop_tx(struct uart_port *port)
 	struct imx_port *sport = (struct imx_port *)port;
 	unsigned long temp;
 
-	/*
-	 * We are maybe in the SMP context, so if the DMA TX thread is running
-	 * on other cpu, we have to wait for it to finish.
-	 */