Commit a7692d8d authored Sep 04, 2014 by Syed Rameez Mustafa

cpuidle: lpm-levels: Report correct C-states to the scheduler

The scheduler currently receives the low power mode level that a CPU
is about to enter whereby 0 indicates the shallowest sleep state and
higher numbers indicate deeper sleep states. The scheduler, however,
operates on the notion of C-states whereby 0 indicates an active state
and a higher numbers indicate different sleep states. Due to this
mismatch the scheduler is unable to distinguish between an active CPU
and a CPU in the shallowest sleep state. Fix this by translating the
low power mode level to the appropriate C-state before communicating
it to the scheduler.

Change-Id: I60d985626cb799d436172c00861f05538c2b382a
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>

parent c5bc590f

drivers/cpuidle/lpm-levels.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -657,7 +657,7 @@ static int lpm_cpuidle_enter(struct cpuidle_device *dev,
		}

		pwr_params = &cluster->cpu->levels[idx].pwr;
		sched_set_cpu_cstate(smp_processor_id(), idx,
		sched_set_cpu_cstate(smp_processor_id(), idx + 1,
		pwr_params->energy_overhead, pwr_params->latency_us);

		cpu_prepare(cluster, idx, true);