[PATCH 4/9] introduce printk support

Jean-Christophe PLAGNIOL-VILLARD plagnioj at jcrosoft.com
Mon Dec 17 02:26:17 EST 2012


On 00:07 Sat 15 Dec     , Sascha Hauer wrote:
> On Thu, Dec 13, 2012 at 05:40:05PM +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> > this will allow to fill the output buffer
> > 
> > and now have 2 output mode pr_xxx for drivers and printf for application
> > 
> > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
> > ---
> >  common/console.c                |   47 +++++++++++++++++++++++++++++++++++++++
> >  include/common.h                |   28 ++++++++++++++---------
> >  include/linux/barebox-wrapper.h |    2 --
> >  3 files changed, 65 insertions(+), 12 deletions(-)
> > 
> > diff --git a/common/console.c b/common/console.c
> > index 2d2d20a..d8fe5b6 100644
> > --- a/common/console.c
> > +++ b/common/console.c
> > @@ -435,6 +435,7 @@ int ctrlc (void)
> >  EXPORT_SYMBOL(ctrlc);
> >  #endif /* ARCH_HAS_CTRC */
> >  
> > +#ifdef CONFIG_CMD_DMESG
> >  #include <command.h>
> >  #include <complete.h>
> >  
> > @@ -454,3 +455,49 @@ BAREBOX_CMD_START(dmesg)
> >  	BAREBOX_CMD_HELP(cmd_dmesg_help)
> >  	BAREBOX_CMD_COMPLETE(empty_complete)
> >  BAREBOX_CMD_END
> > +
> > +int vprintk (const char *fmt, va_list args)
> > +{
> > +	uint i;
> > +	char printbuffer[CFG_PBSIZE];
> > +	char *s = printbuffer;
> > +
> > +	/* For this to work, printbuffer must be larger than
> > +	 * anything we ever want to print.
> > +	 */
> > +	i = vsprintf (printbuffer, fmt, args);
> > +
> > +	/* Print the string */
> > +	puts (printbuffer);
> 
> So when the console is not initialized the characters end up in the
> console_output_fifo which is emptied when the first console is
> initialized. This means it's lost from the dmesg buffer afterwards.

that's why I change this  to just dump instead

Best Regards,
J.
> 
> > +
> > +	if (initialized < CONSOLE_INIT_FULL)
> > +		return i;
> > +
> > +	while (*s) {
> > +		if (*s == '\n')
> > +			kfifo_putc(console_output_fifo, '\r');
> > +		kfifo_putc(console_output_fifo, *s);
> > +		s++;
> > +	}
> 
> You shouldn't use the same buffer for printk messages, use a different
> one instead.
> 
> > +
> > +	return i;
> > +}
> > +EXPORT_SYMBOL(vprintk);
> > +
> > +int printk (const char *fmt, ...)
> > +{
> > +	va_list args;
> > +	uint i;
> > +
> > +	va_start (args, fmt);
> > +
> > +	i = vprintk(fmt, args);
> > +	/* For this to work, printbuffer must be larger than
> > +	 * anything we ever want to print.
> > +	 */
> 
> This comment seems inappropriate here.
> 
> > +	va_end (args);
> > +
> > +	return i;
> > +}
> > +EXPORT_SYMBOL(printk);
> > +#endif
> > diff --git a/include/common.h b/include/common.h
> > index 6256879..168bfd1 100644
> > --- a/include/common.h
> > +++ b/include/common.h
> > @@ -48,22 +48,30 @@
> >  #error "None of __LITTLE_ENDIAN and __BIG_ENDIAN are defined"
> >  #endif
> >  
> > -#define pr_info(fmt, arg...)	printf(fmt, ##arg)
> > -#define pr_notice(fmt, arg...)	printf(fmt, ##arg)
> > -#define pr_err(fmt, arg...)	printf(fmt, ##arg)
> > -#define pr_warning(fmt, arg...)	printf(fmt, ##arg)
> > -#define pr_crit(fmt, arg...)	printf(fmt, ##arg)
> > -#define pr_alert(fmt, arg...)	printf(fmt, ##arg)
> > -#define pr_emerg(fmt, arg...)	printf(fmt, ##arg)
> > +#ifdef CONFIG_CMD_DMESG
> > +int	printk(const char *fmt, ...) __attribute__ ((format(__printf__, 1, 2)));
> > +int	vprintk(const char *fmt, va_list args);
> > +#else
> > +#define printk			printf
> > +#define vprintk			vprintf
> > +#endif
> > +
> > +#define pr_info(fmt, arg...)	printk(fmt, ##arg)
> > +#define pr_notice(fmt, arg...)	printk(fmt, ##arg)
> > +#define pr_err(fmt, arg...)	printk(fmt, ##arg)
> > +#define pr_warning(fmt, arg...)	printk(fmt, ##arg)
> > +#define pr_crit(fmt, arg...)	printk(fmt, ##arg)
> > +#define pr_alert(fmt, arg...)	printk(fmt, ##arg)
> > +#define pr_emerg(fmt, arg...)	printk(fmt, ##arg)
> >  
> >  #ifdef DEBUG
> > -#define pr_debug(fmt, arg...)	printf(fmt, ##arg)
> > +#define pr_debug(fmt, arg...)	printk(fmt, ##arg)
> > +#define debug(fmt, arg...)	printf(fmt, ##arg)
> 
> 'debug' is used in a huge amount of drivers, this would have to be fixed
> when the two functions get a different meaning.
> 
> Sascha
> 
> -- 
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