serial: samsung: enable clock before accessing interrupt mask resister

Ensure that the uart clock is enabled prior to writing to the
interrupt mask register in s3c24xx_serial_resume_noirq function.
Without enabing the uart clock, the uart register cannot be accessed.
Signed-off-by: NYoungmin Nam <youngmin.nam@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/samsung.c

@@ -1916,6 +1916,7 @@ static int s3c24xx_serial_resume(struct device *dev)
 static int s3c24xx_serial_resume_noirq(struct device *dev)
 {
 	struct uart_port *port = s3c24xx_dev_to_port(dev);
+	struct s3c24xx_uart_port *ourport = to_ourport(port);
 
 	if (port) {
 		/* restore IRQ mask */
@@ -1925,7 +1926,9 @@ static int s3c24xx_serial_resume_noirq(struct device *dev)
 				uintm &= ~S3C64XX_UINTM_TXD_MSK;
 			if (rx_enabled(port))
 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
+			clk_prepare_enable(ourport->clk);
 			wr_regl(port, S3C64XX_UINTM, uintm);
+			clk_disable_unprepare(ourport->clk);
 		}
 	}