From 989cc40f806b68678e10203ec3b63d38d0fdd6eb Mon Sep 17 00:00:00 2001
From: =?utf8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Mon, 5 Sep 2022 11:31:20 +0200
Subject: [PATCH] serial: Call flush() before changing baudrate
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Changing baudrate is a sensitive operation. To ensure that U-Boot messages
printed before changing baudrate are not lost, call new U-Boot console
flush() function.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
cmd/load.c | 5 +++++
drivers/serial/serial-uclass.c | 1 +
2 files changed, 6 insertions(+)
diff --git a/cmd/load.c b/cmd/load.c
index e44ae0d56b..5c4f34781d 100644
--- a/cmd/load.c
+++ b/cmd/load.c
@@ -83,6 +83,7 @@ static int do_load_serial(struct cmd_tbl *cmdtp, int flag, int argc,
printf("## Switch baudrate to %d bps and press ENTER ...\n",
load_baudrate);
udelay(50000);
+ flush();
gd->baudrate = load_baudrate;
serial_setbrg();
udelay(50000);
@@ -126,6 +127,7 @@ static int do_load_serial(struct cmd_tbl *cmdtp, int flag, int argc,
printf("## Switch baudrate to %d bps and press ESC ...\n",
current_baudrate);
udelay(50000);
+ flush();
gd->baudrate = current_baudrate;
serial_setbrg();
udelay(50000);
@@ -317,6 +319,7 @@ int do_save_serial(struct cmd_tbl *cmdtp, int flag, int argc,
printf("## Switch baudrate to %d bps and press ESC ...\n",
(int)current_baudrate);
udelay(50000);
+ flush();
gd->baudrate = current_baudrate;
serial_setbrg();
udelay(50000);
@@ -471,6 +474,7 @@ static int do_load_serial_bin(struct cmd_tbl *cmdtp, int flag, int argc,
printf("## Switch baudrate to %d bps and press ENTER ...\n",
load_baudrate);
udelay(50000);
+ flush();
gd->baudrate = load_baudrate;
serial_setbrg();
udelay(50000);
@@ -533,6 +537,7 @@ static int do_load_serial_bin(struct cmd_tbl *cmdtp, int flag, int argc,
printf("## Switch baudrate to %d bps and press ESC ...\n",
current_baudrate);
udelay(50000);
+ flush();
gd->baudrate = current_baudrate;
serial_setbrg();
udelay(50000);
diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c
index 53df10ee85..da3e1eb3ab 100644
--- a/drivers/serial/serial-uclass.c
+++ b/drivers/serial/serial-uclass.c
@@ -476,6 +476,7 @@ static int on_baudrate(const char *name, const char *value, enum env_op op,
printf("## Switch baudrate to %d bps and press ENTER ...\n",
baudrate);
udelay(50000);
+ flush();
}
gd->baudrate = baudrate;
--
2.39.5