Android Wi-Fi 设置带宽代码流程

1 LINUX/android/frameworks/base/wifi/java/android/net/wifi/WifiManager.java

    public void setFrequencyBand(int band, boolean persist) {
        try {
            mService.setFrequencyBand(band, persist);
        } catch (RemoteException e) { }
    }

2 LINUX/android/frameworks/opt/net/wifi/service/java/com/android/server/wifi/WifiServiceImpl.java

    public void setFrequencyBand(int band, boolean persist) {
        enforceChangePermission();
        if (!isDualBandSupported()) return;
        Slog.i(TAG, "WifiService trying to set frequency band to " + band +
                " with persist set to " + persist);
        final long token = Binder.clearCallingIdentity();
        try {
            mWifiStateMachine.setFrequencyBand(band, persist);
        } finally {
            Binder.restoreCallingIdentity(token);
        }
    }

3 LINUX/android/frameworks/opt/net/wifi/service/java/com/android/server/wifi/WifiStateMachine.java

    public void setFrequencyBand(int band, boolean persist) {
        if (persist) {
            Settings.Global.putInt(mContext.getContentResolver(),
                    Settings.Global.WIFI_FREQUENCY_BAND,
                    band);
        }
        sendMessage(CMD_SET_FREQUENCY_BAND, band, 0);
    }

4 LINUX/android/frameworks/opt/net/wifi/service/java/com/android/server/wifi/WifiNative.java

    public boolean setBand(int band) {
        String bandstr;
        if (band == WifiManager.WIFI_FREQUENCY_BAND_5GHZ)
            bandstr = "5G";
        else if (band == WifiManager.WIFI_FREQUENCY_BAND_2GHZ)
            bandstr = "2G";
        else
            bandstr = "AUTO";
        return doBooleanCommand("SET SETBAND " + bandstr);
    }