本来都是硬件的问题，没办法做软件的也得分担责任啊！一般声音相关，不难联想到codec和speaker。那么我在系统起来的时候可不可以不打开speaker呢？反正又没加什么开机音乐，我就让它静静的开机就是。那么什么时候打开呢？系统起来后第一个操作的地方便是speaker打开之时。
一：屏蔽HAL层audio_hw.c：open()
/*adev->pa_handle = open("/dev/pa_dev", O_RDONLY);
if (adev->pa_handle <= 0){
free(adev);
LOGE("Unable to open PA controller, aborting.");
return -EINVAL;
}
ret = ioctl(adev->pa_handle, PA_OPEN, 0);
if (ret < 0){
LOGE("set pa on failed");
}*/
二：在解锁和第一次开机启动launcher的时候
packages/apps/Launcher2/src/com/android/launcher2/Launcher.java：
public void dismissWorkspaceCling(View v) {
｝
frameworks/base/policy/src/com/android/internal/policy/impl/KeyguardViewManager.java：
import java.io.OutputStream;
import java.io.FileOutputStream;//add by caoyi
/**
* Hides the keyguard view
*/
public synchronized void hide() {
if (true) Log.d(TAG, "hide()");
//add by caoyi
String GPIO_PA_FILE = "/dev/pa_dev";
try
{
Log.d(TAG,"gpio_pa open start");
FileOutputStream fos = new FileOutputStream(GPIO_PA_FILE);//记得在驱动open里面拉高PA-SHDN
//byte[] bytes = new byte[2];
//bytes[0] = (byte)('1');
//bytes[1] = '\n';
//fos.write(bytes);
fos.close();
Log.d(TAG,"gpio_pa open succ");
}
catch(Exception e)
{
Log.e(TAG,"gpio_pa open err");
}
//end