[alsa-devel] Improving or replacing snd_printk()

[Takashi Iwai]

At Fri, 31 May 2013 00:06:07 -0700,
Joe Perches wrote:
> 
> On Fri, 2013-05-31 at 08:37 +0200, Takashi Iwai wrote:
> > It's a problem only with snd_printk(), as CONFIG_SND_VERBOSE_PRINTK
> > influences on the behavior of snd_printk() and not on the debug prints
> > with snd_printd() & co.
> 
> Are you're perhaps confused about how CONFIG_SND_VERBOSE_PRINTK
> works with or varies between snd_printd and snd_printk?
> 
> #if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK)
> __printf(4, 5)
> void __snd_printk(unsigned int level, const char *file, int line,
> 		  const char *format, ...);
> 
> ...
> 
> #define snd_printk(fmt, args...) \
> 	__snd_printk(0, __FILE__, __LINE__, fmt, ##args)
> 
> #ifdef CONFIG_SND_DEBUG
> [...]
> #define snd_printd(fmt, args...) \
> 	__snd_printk(1, __FILE__, __LINE__, fmt, ##args)
> 
> I don't see a difference.

Erm, indeed.  I thought we enabled the verobse prinkt always for debug
prints.  But it's not.  It's more reason for dropping
CONFIG_SND_VERBOSE_PRINTK :)

> > Hence, the goal we should achieve is rather to drop
> > CONFIG_SND_VERBOSE_PRINTK.  *This* is the useless thing.
> 
> Maybe.
> 
> > Meanwhile, many snd_printk() messages might start looking annoying
> > with the extra information.  If so, such lines should be replaced with
> > the standard prints like dev_*().  I think almost all snd_printk()
> > like below are better replaced with standard ones.
> 
> below?  Was there something that was supposed to be below?
> Are you referring to the KERN_ERR/urb example above?

Sorry, scratch it.  Just a typo during changing the lines.

> > So, alternatively, we can begin with replacing some snd_printk() with
> > the standard functions, then dropping CONFIG_SND_VERBOSE_PRINTK.
> 
> Dropping CONFIG_SND_VERBOSE_PRINTK would simplify code a bit.
> 
> > I think most of snd_printd() and snd_printdd() can be kept as is.
> > These are just debug messages, after all.
> 
> Some of those are emitted at levels other than KERN_DEBUG.
> I think that odd.

Yeah, they aren't good, but it's a different topic.


Takashi