diff mbox

serial: st-asc: Change default baudrate from 9600 to 115200

Message ID 20170327140340.13459-1-lee.jones@linaro.org
State Accepted
Commit b5090cb46ee7580f848c2ecc4633ada306840328
Headers show

Commit Message

Lee Jones March 27, 2017, 2:03 p.m. UTC
9600 is old school.

Most applications use 115200 as the default baud these days.

Signed-off-by: Lee Jones <lee.jones@linaro.org>

---
 drivers/tty/serial/st-asc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.9.3

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Comments

Greg KH March 27, 2017, 2:18 p.m. UTC | #1
On Mon, Mar 27, 2017 at 03:03:40PM +0100, Lee Jones wrote:
> 9600 is old school.

> 

> Most applications use 115200 as the default baud these days.

> 

> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> ---

>  drivers/tty/serial/st-asc.c | 2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c

> index bcf1d33..be35b53 100644

> --- a/drivers/tty/serial/st-asc.c

> +++ b/drivers/tty/serial/st-asc.c

> @@ -917,7 +917,7 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)

>  static int asc_console_setup(struct console *co, char *options)

>  {

>  	struct asc_port *ascport;

> -	int baud = 9600;

> +	int baud = 115200;


But now you just changed the default behavior :(

Can you guarentee that no one will complain / notice?  If not, then why
even change this?

thanks,

greg k-h
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Lee Jones March 27, 2017, 3:09 p.m. UTC | #2
On Mon, 27 Mar 2017, Greg KH wrote:

> On Mon, Mar 27, 2017 at 03:03:40PM +0100, Lee Jones wrote:

> > 9600 is old school.

> > 

> > Most applications use 115200 as the default baud these days.

> > 

> > Signed-off-by: Lee Jones <lee.jones@linaro.org>

> > ---

> >  drivers/tty/serial/st-asc.c | 2 +-

> >  1 file changed, 1 insertion(+), 1 deletion(-)

> > 

> > diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c

> > index bcf1d33..be35b53 100644

> > --- a/drivers/tty/serial/st-asc.c

> > +++ b/drivers/tty/serial/st-asc.c

> > @@ -917,7 +917,7 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)

> >  static int asc_console_setup(struct console *co, char *options)

> >  {

> >  	struct asc_port *ascport;

> > -	int baud = 9600;

> > +	int baud = 115200;

> 

> But now you just changed the default behavior :(


Yes I am aware, that is the point of the patch. :)

Actually the default behaviour is over-ridden via DT on all of the
platforms we support, and since ST platforms are all now DT-only this
change shouldn't make a noticeable difference for anyone:

arch/arm/boot/dts/
 stih407-b2120.dts:  bootargs = "console=ttyAS0,115200 clk_ignore_unused";
 stih410-b2120.dts:  bootargs = "console=ttyAS0,115200 clk_ignore_unused";
 stih410-b2260.dts:  bootargs = "console=ttyAS1,115200 clk_ignore_unused";
 stih418-b2199.dts:  bootargs = "console=ttyAS0,115200 clk_ignore_unused";

> Can you guarentee that no one will complain / notice? 


Given what I mentioned above, yes, or as near as dammit.

> If not, then why even change this?


Because when using generic booting systems such as U-Boot's Distro
Boot, we need to be as generic as possible.  For this to be successful
everything needs to 'just work' without additional platform specific
burden i.e. non-generic kernel cmdlines.  With this change, we can
boot without specifying serial information on the cmdline to over-ride
the currently incorrect default behaviour.

Even ST's propitiatory debuggers use 115200 by default.  In fact, I
can't find anyone who knows why the default was ever set to 9600.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
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Patrice CHOTARD March 28, 2017, 7:03 a.m. UTC | #3
Hi Lee

On 03/27/2017 04:03 PM, Lee Jones wrote:
> 9600 is old school.

>

> Most applications use 115200 as the default baud these days.

>

> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> ---

>  drivers/tty/serial/st-asc.c | 2 +-

>  1 file changed, 1 insertion(+), 1 deletion(-)

>

> diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c

> index bcf1d33..be35b53 100644

> --- a/drivers/tty/serial/st-asc.c

> +++ b/drivers/tty/serial/st-asc.c

> @@ -917,7 +917,7 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)

>  static int asc_console_setup(struct console *co, char *options)

>  {

>  	struct asc_port *ascport;

> -	int baud = 9600;

> +	int baud = 115200;

>  	int bits = 8;

>  	int parity = 'n';

>  	int flow = 'n';

>


Acked-by: Patrice Chotard <patrice.chotard@st.com>


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diff mbox

Patch

diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
index bcf1d33..be35b53 100644
--- a/drivers/tty/serial/st-asc.c
+++ b/drivers/tty/serial/st-asc.c
@@ -917,7 +917,7 @@  static void asc_console_write(struct console *co, const char *s, unsigned count)
 static int asc_console_setup(struct console *co, char *options)
 {
 	struct asc_port *ascport;
-	int baud = 9600;
+	int baud = 115200;
 	int bits = 8;
 	int parity = 'n';
 	int flow = 'n';