[PATCH 0/2] cpuidle: Avoid returning a disabled C-state from menu governor

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

Hi,

The cpuidle menu governor has a problem that it returns 0 when it can't find
a suitable C-state, but on some systems in some situations 0 may be the
CPUIDLE_DRIVER_STATE_START index and it shouldn't be returned if the corresponding
C-state has been disabled, for example.

The following two patches avoid this issue by modifying the menu governor to
return an error code rather than 0 in those situations.

[1/2] Combine cpuidle_enabled() with cpuidle_select(), because [2/2] makes
      the latter return negative error codes sometimes, so keeping them separate
      is not useful any more.

[2/2] Modify the menu governor to return an error code if the extra "poll" state
      is not available.

Thanks!


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.