[U-Boot] [PATCH] serial: lpc32xx: send CR before LF

Marek Vasut marex at denx.de
Sun Dec 1 16:18:11 CET 2013


Dear Vladimir Zapolskiy,

> Dear Marek Vasut,
> 
> On 12/01/13 01:06, Marek Vasut wrote:
> > Dear Vladimir Zapolskiy,
> > 
> >> On 11/30/13 17:42, Marek Vasut wrote:
> >>> Dear Vladimir Zapolskiy,
> >>> 
> >>>> For LPC32XX high-speed UART it is required to send a carriage return
> >>>> symbol along with line feed.
> >>> 
> >>> Why ?
> >>> 
> >>>> The problem was introduced in e503f90a
> >>>> commit.
> >>>> 
> >>>> Signed-off-by: Vladimir Zapolskiy<vz at mleia.com>
> >>>> Cc: Marek Vasut<marex at denx.de>
> >>>> ---
> >>>> 
> >>>>    drivers/serial/lpc32xx_hsuart.c |    3 +++
> >>>>    1 file changed, 3 insertions(+)
> >>>> 
> >>>> diff --git a/drivers/serial/lpc32xx_hsuart.c
> >>>> b/drivers/serial/lpc32xx_hsuart.c index 9c7c621..c8926a8 100644
> >>>> --- a/drivers/serial/lpc32xx_hsuart.c
> >>>> +++ b/drivers/serial/lpc32xx_hsuart.c
> >>>> @@ -38,6 +38,9 @@ static int lpc32xx_serial_getc(void)
> >>>> 
> >>>>    static void lpc32xx_serial_putc(const char c)
> >>>>    {
> >>>> 
> >>>> +	if (c == '\n')
> >>>> +		serial_putc('\r');
> >>>> +
> >>>> 
> >>>>    	writel(c,&hsuart->tx);
> >>>>    	
> >>>>    	/* Wait for character to be sent */
> >>> 
> >>> btw. I have a feeling each and every driver does send CR-LF combo and
> >>> emulates it this way. Maybe this should eventually go into common code
> >>> ? But that's just a suggestion for future improvement.
> >> 
> >> No objections from my side, however it seems that not every particular
> >> serial
> >> controller requires such a hook, for code generalization it may be good
> >> to have
> >> it for all drivers, but strict enforcement may be redundant for some
> >> subset.
> > 
> > This would need further investigation, very detailed one.
> 
> if you anticipate that such investigation and testing will take significant
> amount of time, I'd be glad, if you let the regression fix in before doing
> code generalization.

By all means,

Acked-by: Marek Vasut <marex at denx.de>

Best regards,
Marek Vasut


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