struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu);
int latency_req = cpuidle_governor_latency_req(dev->cpu);
unsigned int duration_us, count;
- int max_early_idx, idx, i;
+ int max_early_idx, constraint_idx, idx, i;
ktime_t delta_tick;
if (dev->last_state_idx >= 0) {
count = 0;
max_early_idx = -1;
+ constraint_idx = drv->state_count;
idx = -1;
for (i = 0; i < drv->state_count; i++) {
if (s->target_residency > duration_us)
break;
- if (s->exit_latency > latency_req) {
- /*
- * If we break out of the loop for latency reasons, use
- * the target residency of the selected state as the
- * expected idle duration to avoid stopping the tick
- * as long as that target residency is low enough.
- */
- duration_us = drv->states[idx].target_residency;
- goto refine;
- }
+ if (s->exit_latency > latency_req && constraint_idx > i)
+ constraint_idx = i;
idx = i;
duration_us = drv->states[idx].target_residency;
}
-refine:
+ /*
+ * If there is a latency constraint, it may be necessary to use a
+ * shallower idle state than the one selected so far.
+ */
+ if (constraint_idx < idx)
+ idx = constraint_idx;
+
if (idx < 0) {
idx = 0; /* No states enabled. Must use 0. */
} else if (idx > 0) {
/*
* Count and sum the most recent idle duration values less than
- * the target residency of the state selected so far, find the
- * max.
+ * the current expected idle duration value.
*/
for (i = 0; i < INTERVALS; i++) {
unsigned int val = cpu_data->intervals[i];
- if (val >= drv->states[idx].target_residency)
+ if (val >= duration_us)
continue;
count++;
* would be too shallow.
*/
if (!(tick_nohz_tick_stopped() && avg_us < TICK_USEC)) {
- idx = teo_find_shallower_state(drv, dev, idx, avg_us);
duration_us = avg_us;
+ if (drv->states[idx].target_residency > avg_us)
+ idx = teo_find_shallower_state(drv, dev,
+ idx, avg_us);
}
}
}