android: Couldn't open /sys/power/wait_for_fb_sleep or /sys/power/wait_for_fb_wake

在android系统启动的时候，报这个错误：Couldn't open /sys/power/wait_for_fb_sleep or /sys/power/wait_for_fb_wake

power配置必须指定sysfs模式

x CONFIG_FB_EARLYSUSPEND: x
x x
x Register early suspend handler that notifies and waits for x
x user-space through sysfs when user-space should stop drawing x
x to the screen and notifies user-space when it should resume. x
x Symbol: FB_EARLYSUSPEND [=y] x
x Prompt:Sysfs interface x
x Defined at kernel/power/Kconfig:177 x
x Depends on: <choice> && HAS_EARLYSUSPEND x
x Location: x
x -> Power management options x
x -> User-space screen access (<choice> [=y])