[PATCH v2 5/6] serial: Call flush() before changing baudrate

Pali Rohár
2022-08-11T12:40:16Z

Changing baudrate is 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>
---
cmd/load.c | 5 +++++
drivers/serial/serial-uclass.c | 1 +
drivers/serial/serial.c | 1 +
3 files changed, 7 insertions(+)

diff --git a/cmd/load.c b/cmd/load.c
index e44ae0d56b75..5c4f34781d45 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 4e32270d4660..0f6860d9100e 100644
--- a/drivers/serial/serial-uclass.c
+++ b/drivers/serial/serial-uclass.c
@@ -527,6 +527,7 @@ 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;
diff --git a/drivers/serial/serial.c b/drivers/serial/serial.c
index 6cdbb89841c1..4b525b644928 100644
--- a/drivers/serial/serial.c
+++ b/drivers/serial/serial.c
@@ -81,6 +81,7 @@ 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;
--
2.20.1