Re: [PATCH] PM: Hide CONFIG_PM from users

From: Rafael J. Wysocki
Date: Mon Feb 07 2011 - 14:14:34 EST


On Monday, February 07, 2011, Mark Brown wrote:
> It is very rare to find a current system which is both sufficiently
> resource constrained to want to compile out power management support
> and sufficiently power insensitive to be able to tolerate doing so.
> Since having the configuration option requires non-zero effort to
> maintain, with ifdefery in most drivers, but it is used with vanishing
> rarity it is simpler to just remove the option.
>
> Begin doing so by hiding it from users - this should attract complaints
> from any active users. The option is left disabled for the IA64 Ski
> simulator which is a partial simulator for IA64 systems mostly missing
> device support. This is a very limited use case which is unlikely to
> ever want to enable most drivers.
>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
> kernel/power/Kconfig | 21 ++-------------------
> 1 files changed, 2 insertions(+), 19 deletions(-)
>
> diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
> index 2657299..99e3c52 100644
> --- a/kernel/power/Kconfig
> +++ b/kernel/power/Kconfig
> @@ -1,23 +1,6 @@
> config PM
> - bool "Power Management support"
> - depends on !IA64_HP_SIM
> - ---help---
> - "Power Management" means that parts of your computer are shut
> - off or put into a power conserving "sleep" mode if they are not
> - being used. There are two competing standards for doing this: APM
> - and ACPI. If you want to use either one, say Y here and then also
> - to the requisite support below.
> -
> - Power Management is most important for battery powered laptop
> - computers; if you have a laptop, check out the Linux Laptop home
> - page on the WWW at <http://www.linux-on-laptops.com/> or
> - Tuxmobil - Linux on Mobile Computers at <http://www.tuxmobil.org/>
> - and the Battery Powered Linux mini-HOWTO, available from
> - <http://www.tldp.org/docs.html#howto>.
> -
> - Note that, even if you say N here, Linux on the x86 architecture
> - will issue the hlt instruction if nothing is to be done, thereby
> - sending the processor to sleep and saving power.
> + bool
> + default y if !IA64_HP_SIM
>
> config PM_DEBUG
> bool "Power Management Debug Support"

I think it would be better to simply rename CONFIG_PM_OPS into CONFIG_PM.

However, there's a number of things that I'm afraid wouldn't build correctly
if none of CONFIG_PM_SLEEP and CONFIG_PM_RUNTIME were set in that case.

Anyway, I'll try to prepare a patch doing that and see what happens.
Stay tuned.

Thanks,
Rafael
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