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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-12-13 09:56:13 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-12-27 11:02:08 +0100 |
| commit | 75a80267410e38ab76c4ceb39753f96d72113781 (patch) | |
| tree | 08c172e0d40ae21128686957ec078065ef4bc1d0 /drivers/cpuidle/cpuidle.c | |
| parent | 18734958e9bfbc055805d110a38dc76307eba742 (diff) | |
| download | lwn-75a80267410e38ab76c4ceb39753f96d72113781.tar.gz lwn-75a80267410e38ab76c4ceb39753f96d72113781.zip | |
cpuidle: Allow idle states to be disabled by default
In certain situations it may be useful to prevent some idle states
from being used by default while allowing user space to enable them
later on.
For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to
mark idle states that should be disabled by default, make the core
set CPUIDLE_STATE_DISABLED_BY_USER for those states at the
initialization time and add a new state attribute in sysfs,
"default_status", to inform user space of the initial status of
the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it,
"enabled" otherwise).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpuidle/cpuidle.c')
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 33d19c8eb027..a2af7bb8f0a5 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -572,10 +572,14 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) if (!try_module_get(drv->owner)) return -EINVAL; - for (i = 0; i < drv->state_count; i++) + for (i = 0; i < drv->state_count; i++) { if (drv->states[i].flags & CPUIDLE_FLAG_UNUSABLE) dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER; + if (drv->states[i].flags & CPUIDLE_FLAG_OFF) + dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER; + } + per_cpu(cpuidle_devices, dev->cpu) = dev; list_add(&dev->device_list, &cpuidle_detected_devices); |