1 files changed, 40 insertions, 0 deletions
diff --git a/target/linux/layerscape/patches-5.4/819-uart-0002-tty-serial-fsl_lpuart-add-modem-device-reset.patch b/target/linux/layerscape/patches-5.4/819-uart-0002-tty-serial-fsl_lpuart-add-modem-device-reset.patch
new file mode 100644
index 0000000000..37fd23d205
--- /dev/null
+++ b/target/linux/layerscape/patches-5.4/819-uart-0002-tty-serial-fsl_lpuart-add-modem-device-reset.patch
@@ -0,0 +1,40 @@
+From 5b05462e88dc87d83566d04dd196b4f3d9dc0eef Mon Sep 17 00:00:00 2001
+From: Fugang Duan <fugang.duan@nxp.com>
+Date: Mon, 28 Jan 2019 10:12:52 +0800
+Subject: [PATCH] tty: serial: fsl_lpuart: add modem device reset
+
+Add modem device reset, wthether to reset depend on dts configuration.
+
+Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
+---
+ drivers/tty/serial/fsl_lpuart.c | 10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+--- a/drivers/tty/serial/fsl_lpuart.c
++++ b/drivers/tty/serial/fsl_lpuart.c
+@@ -22,6 +22,7 @@
+ #include <linux/of_dma.h>
+ #include <linux/pm_domain.h>
+ #include <linux/pm_runtime.h>
++#include <linux/reset.h>
+ #include <linux/serial_core.h>
+ #include <linux/slab.h>
+ #include <linux/tty_flip.h>
+@@ -1544,8 +1545,17 @@ static void lpuart32_configure(struct lp
+ static int lpuart32_startup(struct uart_port *port)
+ {
+ 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
++	struct tty_port *tty_port = &sport->port.state->port;
+ 	unsigned long flags;
+ 	unsigned long temp;
++	int ret;
++
++	/* some modem may need reset */
++	if (!tty_port_suspended(tty_port)) {
++		ret = device_reset(sport->port.dev);
++		if (ret && ret != -ENOENT)
++			return ret;
++	}
+ 
+ 	/* determine FIFO size */
+ 	temp = lpuart32_read(&sport->port, UARTFIFO);