UPSTREAM: cpuidle: menu: Retain tick when shallow state is selected

The case addressed by commit 5ef499cd571c (cpuidle: menu: Handle
stopped tick more aggressively) in the stopped tick case is present
when the tick has not been stopped yet too.  Namely, if only two CPU
idle states, shallow state A with target residency significantly
below the tick boundary and deep state B with target residency
significantly above it, are available and the predicted idle
duration is above the tick boundary, but below the target residency
of state B, state A will be selected and the CPU may spend indefinite
amount of time in it, which is not quite energy-efficient.

However, if the tick has not been stopped yet and the governor is
about to select a shallow idle state for the CPU even though the idle
duration predicted by it is above the tick boundary, it should be
fine to wake up the CPU early, so the tick can be retained then and
the governor will have a chance to select a deeper state when it runs
next time.

[Note that when this really happens, it will make the idle duration
 predictor believe that the CPU might be idle longer than predicted,
 which will make it more likely to predict longer idle durations going
 forward, but that will also cause deeper idle states to be selected
 going forward, on average, which is what's needed here.]

Bug: 254441685
Fixes: 87c9fe6ee495 (cpuidle: menu: Avoid selecting shallow states with stopped tick)
Reported-by: Leo Yan <leo.yan@linaro.org>
Cc: 4.17+ <stable@vger.kernel.org> # 4.17+: 5ef499cd571c (cpuidle: menu: Handle ...)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit 757ab15c3f4968b5a29caf3fe8b67660ce84c3cd)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: Ie337749f46f9f21f26e25acf87006ee463da78cf

1 files changed, 0 insertions, 0 deletions

diff --git a/common b/common
-Subproject 0a203f3e16e6bedbb4bc54fc38813cd016c04d8
+Subproject 48fa89bc73388370a88abcdf3c61b352a3457f8