[U-Boot] [PATCH v4 2/6] serial: add UniPhier serial driver

[Marek Vasut]

On Friday, September 05, 2014 at 02:03:38 PM, Masahiro Yamada wrote:
> Hi Marek,
> 
> 
> 
> On Fri, 5 Sep 2014 12:35:18 +0200
> 
> Marek Vasut <marex at denx.de> wrote:
> > On Friday, September 05, 2014 at 07:50:19 AM, Masahiro Yamada wrote:
> > > The driver for on-chip UART used on Panasonic UniPhier platform.
> > > 
> > > Signed-off-by: Masahiro Yamada <yamada.m at jp.panasonic.com>
> > 
> > [...]
> > 
> > Hi!
> > 
> > > +static void uniphier_serial_putc(struct uniphier_serial *port, const
> > > char c) +{
> > > +	if (c == '\n')
> > > +		uniphier_serial_putc(port, '\r');
> > 
> > Just curious, but what is the concensus about inserting \r upon \n ?
> > Shouldn't this be something that the "upper layers" do consistently ? I
> > recall seeing this in some drivers and not seeing this in the others, so
> > I wonder why this is like so ...
> 
> This converts "\n" to "\r\n".

Apologies, you're right. This is what I meant.

> Without this conversion, CarriageReturn is not provided,
> which means the cursor goes to the next line, but
> column position does not change.
> 
> 
> For example,
> 
> printf("Hello\nWorld\n");
> 
> will be displayed on (at least my) terminal emulator like this:
> 
> 
> Hello
>      World
> 
> 
> With the conversion code, it will be displaye as follows:
> 
> Hello
> World
> 
> Perhaps the behavior might depend on
> which therminal emulator you are using.
> (also depend on the preference
> how LF and CR are handled.)

I use minicom . You do have a point that it might be it.

> Maybe we can move  "\n -> \r\n" logic
> to the upper layer and allow users to enable/disable it
> with a CONFIG_ option.

Either that or make it even run-time configurable, esp. if this depends on the 
users' terminal setting.

Best regards,
Marek Vasut