From 0d4ed4e27a4cb180af395fa3d7aa98d79f3d3015 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Fri, 4 May 2012 21:06:19 -0700 Subject: [PATCH] power_supply: Make the core a boolean instead of a tristate On Mon, Apr 02, 2012 at 01:53:23PM +1000, Benjamin Herrenschmidt wrote: > > drivers/built-in.o: In function `.nouveau_pm_trigger': > > (.text+0xa56e8): undefined reference to `.power_supply_is_system_supplied' > > > > nouveau probably needs to depends on CONFIG_POWER_SUPPLY to force a module > > build with the latter is =m > > Ok, not that trivial... > > The problem is more like POWER_SUPPLY should be a bool, not a tristate. > > If you think about it: you don't want things like nouveau to depend on a > random subsystem like that, people will never get it. In fact, > POWER_SUPPLY provides empty inline stubs when not enabled, so that's > really designed to not have depends... > > However that -cannot- work if POWER_SUPPLY is modular and the drivers > who use it are not. > > The only fixes here that make sense I can think of > that don't also involve Kconfig horrors are: > > - Ugly: in power_supply.h, use the extern variant if > > defined(CONFIG_POWER_SUPPLY) || > (defined(CONFIG_POWER_SUPPLY_MODULE) && defined(MODULE)) > > IE. use the stub if power supply is a module and what is being built is > built-in. Of course that's not only ugly, it somewhat sucks from a user > perspective as the subsystem now exists but can't be used by some > drivers... > > - Better: Just make the bloody thing a bool :-) The power supply > framework itself is small enough, just make it a boolean option and > avoid the problem entirely. The actual power supply sub drivers can > remain modular of course. Suggested-by: Benjamin Herrenschmidt Signed-off-by: Anton Vorontsov --- drivers/power/Kconfig | 2 +- include/linux/power_supply.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig index 99dc29f2f2f2..0c52a4079124 100644 --- a/drivers/power/Kconfig +++ b/drivers/power/Kconfig @@ -1,5 +1,5 @@ menuconfig POWER_SUPPLY - tristate "Power supply class support" + bool "Power supply class support" help Say Y here to enable power supply class support. This allows power supply (batteries, AC, USB) monitoring by userspace diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index fd17ae0f9c20..3b912bee28d1 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -212,7 +212,7 @@ extern void power_supply_changed(struct power_supply *psy); extern int power_supply_am_i_supplied(struct power_supply *psy); extern int power_supply_set_battery_charged(struct power_supply *psy); -#if defined(CONFIG_POWER_SUPPLY) || defined(CONFIG_POWER_SUPPLY_MODULE) +#ifdef CONFIG_POWER_SUPPLY extern int power_supply_is_system_supplied(void); #else static inline int power_supply_is_system_supplied(void) { return -ENOSYS; } -- 2.30.2