On Fri 11 Sep 10:00 CDT 2020, Douglas Anderson wrote:
> Commit c5cbc78acf69 ("tty: serial: qcom_geni_serial: Initialize baud
> in qcom_geni_console_setup") fixed a bug by initting a variable that
> was used in some cases without initialization. However, the "default"
> baud rate picked by that CL was probably not the best choice. The
> chances that anyone out there is trying to run a system with kernel
> messages piped out over a 9600 baud serial port is just about nil.
> Console messages are printed in a blocking manner. At 9600 baud we
> print about 1 character per millisecond which means that printing a
> 40-byte message to the console will take ~40 ms. While it would
> probably work, it's going to make boot _very_ slow and probably cause
> the occasional timeout here and there in drivers (heck, even at 115200
> console delays can wreck havoc).
>
> This has already bit at least two people that I'm aware of that tried
> to enable serial console by just adding "console=ttyMSM0" (instead of
> "console=ttyMSM0,115200n8") to the command line, so it seems like it'd
> be nice to fix.
>
> Let's switch the default to 115200.
>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> ---
>
> drivers/tty/serial/qcom_geni_serial.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> index f0b1b47c3abc..e390ffc8bbbd 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -1107,7 +1107,7 @@ static int qcom_geni_console_setup(struct console *co, char *options)
> {
> struct uart_port *uport;
> struct qcom_geni_serial_port *port;
> - int baud = 9600;
> + int baud = 115200;
> int bits = 8;
> int parity = 'n';
> int flow = 'n';
> --
> 2.28.0.618.gf4bc123cb7-goog
>
