Re: [RFC v2 3/4] mac80211: use static keys for hw flags

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2015-11-11 at 02:22 +0200, Luca Coelho wrote:
> 
> Now that you have all these options in Kconfig, wouldn't it be
> possible
> to remove the calls to the "static" ieee80211_hw_set() in the drivers
> and somehow set all the flags that are defined in Kconfig
> automatically?
> 

Since Kconfig flags are global (across multiple drivers) I don't really
see a way to do that.

I'd *love*, however, to have an "increment" in Kconfig, then I could
get rid of the _OFF ones:

config MAC80211_NUM_DRIVERS
	int

config MAC80211_HW_HAS_RATE_CONTROL
	int

config MY_DRIVER
	depends on MAC80211
	increment MAC80211_NUM_DRIVERS
	increment MAC80211_HW_MYFLAG


and then later

if (CONFIG_MAC80211_HW_MYFLAG == 0)
	/* optimise for flag OFF */
else if (CONFIG_MAC80211_HW_MYFLAG > 0 &&
         CONFIG_MAC80211_NUM_DRIVERS == CONFIG_MAC80211_HW_MYFLAG)
	/* optimise for flag ON */
else if (CONFIG_MAC80211_HW_MYFLAG > 0)
	/* don't optimise */

That's far more maintainable in the long term, since each driver only
needs to list in its Kconfig the flags it *wants*, not *all*.

Maybe I'll try to see if I can hack Kconfig to do that.

johannes