@@ -478,15 +478,23 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
- set the power.last_busy field to the current time
void pm_runtime_use_autosuspend(struct device *dev);
- - set the power.use_autosuspend flag, enabling autosuspend delays
+ - set the power.use_autosuspend flag, enabling autosuspend delays; call
+ pm_runtime_get_sync if the flag was previously cleared and
+ power.autosuspend_delay is negative
void pm_runtime_dont_use_autosuspend(struct device *dev);
- - clear the power.use_autosuspend flag, disabling autosuspend delays
+ - clear the power.use_autosuspend flag, disabling autosuspend delays;
+ decrement the device's usage counter if the flag was previously set and
+ power.autosuspend_delay is negative; call pm_runtime_idle
void pm_runtime_set_autosuspend_delay(struct device *dev, int delay);
- set the power.autosuspend_delay value to 'delay' (expressed in
milliseconds); if 'delay' is negative then runtime suspends are
- prevented
+ prevented; if power.use_autosuspend is set, pm_runtime_get_sync may be
+ called or the device's usage counter may be decremented and
+ pm_runtime_idle called depending on if power.autosuspend_delay is
+ changed to or from a negative value; if power.use_autosuspend is clear,
+ pm_runtime_idle is called
unsigned long pm_runtime_autosuspend_expiration(struct device *dev);
- calculate the time when the current autosuspend delay period will expire,
Document the fact that the autosuspend delay and enable helpers may change the power.usage_count and resume or suspend a device depending on the values of power.autosuspend_delay and power.use_autosuspend. Note that this means that a driver must disable autosuspend before disabling runtime pm on probe errors and on driver unbind if the device is to be suspended upon return (as a negative delay may otherwise keep the device resumed). Signed-off-by: Johan Hovold <johan@kernel.org> --- Documentation/power/runtime_pm.txt | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)