android 5.1禁止休眠

1.  修改default值，不自动休眠

      /frameworks/base/packages/SettingsProvider/res/values/defaults.xml

      修改def_screen_off_timeout为-1

2.frameworks/base/services/core/java/com/android/server/power/PowerManagerService.java

修改PowerManagerService.java文件getScreenOffTimeoutLocked()函数

 private int getScreenOffTimeoutLocked() {
         int timeout = mScreenOffTimeoutSetting;
         if (isMaximumScreenOffTimeoutFromDeviceAdminEnforcedLocked()) {
             timeout = Math.min(timeout, mMaximumScreenOffTimeoutFromDeviceAdmin);
         }
         if (mUserActivityTimeoutOverrideFromWindowManager >= 0) {
             timeout = (int)Math.min(timeout, mUserActivityTimeoutOverrideFromWindowManager);
         }

         return Math.max(timeout, MINIMUM_SCREEN_OFF_TIMEOUT);
     }

修改后:

 int nosleep;
 int timeout = mScreenOffTimeoutSetting;
 if (isMaximumScreenOffTimeoutFromDeviceAdminEnforcedLocked()) {
     timeout = Math.min(timeout, mMaximumScreenOffTimeoutFromDeviceAdmin);
 }
 if (mUserActivityTimeoutOverrideFromWindowManager >= 0) {
     timeout = (int)Math.min(timeout, mUserActivityTimeoutOverrideFromWindowManager);
 }
 nosleep = mScreenOffTimeoutSetting;
 if(nosleep  < 0)
 {
     nosleep = mMaximumScreenOffTimeoutFromDeviceAdmin ;
     return Math.max(nosleep, mMaximumScreenOffTimeoutFromDeviceAdmin);
 }
 return Math.max(timeout, MINIMUM_SCREEN_OFF_TIMEOUT);