From: Guangqing Zhu <[email protected]>
The injected idle duration should be greater than the idle state min
residency, otherwise we end up consuming more energy and potentially invert
the mitigation effect.
In function __cpuidle_cooling_register(), if
of_property_read_u32(np, "exit-latency-us", &latency_us) is failed, then
maybe we should not use latency_us. In this case, a zero latency_us for
forced_idle_latency_limit_ns is better than UMAX_INT. It means to use
governors in the usual way.
Signed-off-by: Guangqing Zhu <[email protected]>
---
drivers/powercap/idle_inject.c | 1 -
drivers/thermal/cpuidle_cooling.c | 8 +++++++-
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/powercap/idle_inject.c b/drivers/powercap/idle_inject.c
index 6e1a0043c411..d76eef1e9387 100644
--- a/drivers/powercap/idle_inject.c
+++ b/drivers/powercap/idle_inject.c
@@ -309,7 +309,6 @@ struct idle_inject_device *idle_inject_register(struct cpumask *cpumask)
cpumask_copy(to_cpumask(ii_dev->cpumask), cpumask);
hrtimer_init(&ii_dev->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
ii_dev->timer.function = idle_inject_timer_fn;
- ii_dev->latency_us = UINT_MAX;
for_each_cpu(cpu, to_cpumask(ii_dev->cpumask)) {
diff --git a/drivers/thermal/cpuidle_cooling.c b/drivers/thermal/cpuidle_cooling.c
index 7ecab4b16b29..de770eb5b2ba 100644
--- a/drivers/thermal/cpuidle_cooling.c
+++ b/drivers/thermal/cpuidle_cooling.c
@@ -175,7 +175,8 @@ static int __cpuidle_cooling_register(struct device_node *np,
struct cpuidle_cooling_device *idle_cdev;
struct thermal_cooling_device *cdev;
unsigned int idle_duration_us = TICK_USEC;
- unsigned int latency_us = UINT_MAX;
+ unsigned int latency_us = 0;
+ unsigned int residency_us = UINT_MAX;
char dev_name[THERMAL_NAME_LENGTH];
int id, ret;
@@ -199,6 +200,11 @@ static int __cpuidle_cooling_register(struct device_node *np,
of_property_read_u32(np, "duration-us", &idle_duration_us);
of_property_read_u32(np, "exit-latency-us", &latency_us);
+ of_property_read_u32(np, "min-residency-us", &residency_us);
+ if (idle_duration_us <= residency_us) {
+ ret = -EINVAL;
+ goto out_unregister;
+ }
idle_inject_set_duration(ii_dev, TICK_USEC, idle_duration_us);
idle_inject_set_latency(ii_dev, latency_us);
--
2.17.1