What: /sys/kernel/wakeup_reasons/last_resume_reason Date: February 2014 Contact: Ruchi Kandoi Description: The /sys/kernel/wakeup_reasons/last_resume_reason is used to report wakeup reasons after system exited suspend. What: /sys/kernel/wakeup_reasons/last_suspend_time Date: March 2015 Contact: jinqian Description: The /sys/kernel/wakeup_reasons/last_suspend_time is used to report time spent in last suspend cycle. It contains two numbers (in seconds) separated by space. First number is the time spent in suspend and resume processes. Second number is the time spent in sleep state.