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path: root/drivers/cpuidle/cpuidle.c
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Diffstat (limited to 'drivers/cpuidle/cpuidle.c')
-rw-r--r--drivers/cpuidle/cpuidle.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 0835da449db8..c7876e9e024f 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -184,20 +184,22 @@ static noinstr void enter_s2idle_proper(struct cpuidle_driver *drv,
* cpuidle_enter_s2idle - Enter an idle state suitable for suspend-to-idle.
* @drv: cpuidle driver for the given CPU.
* @dev: cpuidle device for the given CPU.
+ * @latency_limit_ns: Idle state exit latency limit
*
* If there are states with the ->enter_s2idle callback, find the deepest of
* them and enter it with frozen tick.
*/
-int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev)
+int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
+ u64 latency_limit_ns)
{
int index;
/*
- * Find the deepest state with ->enter_s2idle present, which guarantees
- * that interrupts won't be enabled when it exits and allows the tick to
- * be frozen safely.
+ * Find the deepest state with ->enter_s2idle present that meets the
+ * specified latency limit, which guarantees that interrupts won't be
+ * enabled when it exits and allows the tick to be frozen safely.
*/
- index = find_deepest_state(drv, dev, U64_MAX, 0, true);
+ index = find_deepest_state(drv, dev, latency_limit_ns, 0, true);
if (index > 0) {
enter_s2idle_proper(drv, dev, index);
local_irq_enable();
@@ -635,8 +637,14 @@ static void __cpuidle_device_init(struct cpuidle_device *dev)
static int __cpuidle_register_device(struct cpuidle_device *dev)
{
struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+ unsigned int cpu = dev->cpu;
int i, ret;
+ if (per_cpu(cpuidle_devices, cpu)) {
+ pr_info("CPU%d: cpuidle device already registered\n", cpu);
+ return -EEXIST;
+ }
+
if (!try_module_get(drv->owner))
return -EINVAL;
@@ -648,7 +656,7 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER;
}
- per_cpu(cpuidle_devices, dev->cpu) = dev;
+ per_cpu(cpuidle_devices, cpu) = dev;
list_add(&dev->device_list, &cpuidle_detected_devices);
ret = cpuidle_coupled_register_device(dev);