Re: [PATCH] PM: Hide CONFIG_PM from users

[Frank Rowand <frank.rowand@am.sony.com>]

On 02/07/11 04:22, 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.

Proof by assertion that it is used with vanishing rarity.

> 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.

That is not a good method of getting feedback from users.

 1) It immediately removes the ability to have CONFIG_PM undefined,
    without first giving active users a chance to provide feedback.

 2) The removal of that ability is not obvious ("make oldconfig" does
    not say anything about CONFIG_PM).  It is easy to overlook a
    config change that happens silently.

 3) The active users may not move to a newer version of the kernel
    that contains this change until after it has been decided that
    there are no users of the config option since no one complained
    in a timely manner.

Would it be appropriate to use Documentation/feature-removal-schedule.txt
if this truly will be removed?

-Frank