Re: [PATCH wireless-next 2/3] ath5k: Introduce _ath5k_printk toreduce code/text

From: Joe Perches
Date: Mon Mar 19 2012 - 01:18:57 EST


On Sun, 2012-03-18 at 21:36 -0700, Adrian Chadd wrote:
> Hi,

Hi Adrian.

> So the reason this is a macro in the FreeBSD HAL is so that the args
> aren't evaluated unless the level (or debug bitmap in my case) fires
> off.
>
> Otherwise compiling in debugging will cause a _lot_ of spurious
> register reads to occur that are then tossed. This was one of the big
> reasons for instability and slow performance when AH_DEBUG was
> enabled.

That doesn't make any sense in this case.

It's either a call to printk or _ath5_printk
but it's still a call to a function.

+void __printf(3, 4)
+_ath5k_printk(const struct ath5k_hw *ah, const char *level,
+ const char *fmt, ...);
+
#define ATH5K_PRINTK(_sc, _level, _fmt, ...) \
- printk(_level pr_fmt("%s%s" _fmt), \
- ((_sc) && (_sc)->hw) ? wiphy_name((_sc)->hw->wiphy) : "", \
- ((_sc) && (_sc)->hw) ? ": " : "", \
- ##__VA_ARGS__)
+ _ath5k_printk(_sc, _level, _fmt, ##__VA_ARGS__)

If there are level/mask tests to macros that
are used to call ATH5K_PRINTK, that still
works. As far as I can tell, there aren't
any uses of macros like that.

cheers, Joe


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