Use new wifi cmd rssi-approx when polling.

Cheaper approx call should be used when polling every 3 sec for
wifi signal strength.  Fixes bug 1903653.

3 files changed, 22 insertions, 6 deletions

diff --git a/core/jni/android_net_wifi_Wifi.cpp b/core/jni/android_net_wifi_Wifi.cpp
index 9f93e2f..75ae4d9 100644
--- a/core/jni/android_net_wifi_Wifi.cpp
+++ b/core/jni/android_net_wifi_Wifi.cpp
@@ -307,14 +307,15 @@ static jboolean android_net_wifi_stopPacketFiltering(JNIEnv* env, jobject clazz)
     return result;
 }
 
-static jint android_net_wifi_getRssiCommand(JNIEnv* env, jobject clazz)
+static jint android_net_wifi_getRssiHelper(const char *cmd)
 {
     char reply[256];
     int rssi = -200;
 
-    if (doCommand("DRIVER RSSI", reply, sizeof(reply)) != 0) {
+    if (doCommand(cmd, reply, sizeof(reply)) != 0) {
         return (jint)-1;
     }
+
     // reply comes back in the form "<SSID> rssi XX" where XX is the
     // number we're interested in.  if we're associating, it returns "OK".
     // beware - <SSID> can contain spaces.
@@ -328,6 +329,16 @@ static jint android_net_wifi_getRssiCommand(JNIEnv* env, jobject clazz)
     return (jint)rssi;
 }
 
+static jint android_net_wifi_getRssiCommand(JNIEnv* env, jobject clazz)
+{
+    return android_net_wifi_getRssiHelper("DRIVER RSSI");
+}
+
+static jint android_net_wifi_getRssiApproxCommand(JNIEnv* env, jobject clazz)
+{
+    return android_net_wifi_getRssiHelper("DRIVER RSSI-APPROX");
+}
+
 static jint android_net_wifi_getLinkSpeedCommand(JNIEnv* env, jobject clazz)
 {
     char reply[256];
@@ -523,6 +534,8 @@ static JNINativeMethod gWifiMethods[] = {
     { "setBluetoothCoexistenceScanModeCommand", "(Z)Z",
     		(void*) android_net_wifi_setBluetoothCoexistenceScanModeCommand },
     { "getRssiCommand", "()I", (void*) android_net_wifi_getRssiCommand },
+    { "getRssiApproxCommand", "()I",
+            (void*) android_net_wifi_getRssiApproxCommand},
     { "getLinkSpeedCommand", "()I", (void*) android_net_wifi_getLinkSpeedCommand },
     { "getMacAddressCommand", "()Ljava/lang/String;", (void*) android_net_wifi_getMacAddressCommand },
     { "saveConfigCommand", "()Z", (void*) android_net_wifi_saveConfigCommand },
diff --git a/wifi/java/android/net/wifi/WifiNative.java b/wifi/java/android/net/wifi/WifiNative.java
index 3851ac0..0920567 100644
--- a/wifi/java/android/net/wifi/WifiNative.java
+++ b/wifi/java/android/net/wifi/WifiNative.java
@@ -79,6 +79,8 @@ public class WifiNative {
 
     public native static int getRssiCommand();
 
+    public native static int getRssiApproxCommand();
+
     public native static int getLinkSpeedCommand();
 
     public native static String getMacAddressCommand();
diff --git a/wifi/java/android/net/wifi/WifiStateTracker.java b/wifi/java/android/net/wifi/WifiStateTracker.java
index e6f4130..7e95f79 100644
--- a/wifi/java/android/net/wifi/WifiStateTracker.java
+++ b/wifi/java/android/net/wifi/WifiStateTracker.java
@@ -1029,7 +1029,7 @@ public class WifiStateTracker extends NetworkStateTracker {
 
             case EVENT_POLL_INTERVAL:
                 if (mWifiInfo.getSupplicantState() != SupplicantState.UNINITIALIZED) {
-                    requestPolledInfo(mWifiInfo);
+                    requestPolledInfo(mWifiInfo, true);
                     if (mWifiInfo.getSupplicantState() == SupplicantState.COMPLETED) {
                         setPollTimer();
                     }
@@ -1276,7 +1276,7 @@ public class WifiStateTracker extends NetworkStateTracker {
      */
     public WifiInfo requestConnectionInfo() {
         requestConnectionStatus(mWifiInfo);
-        requestPolledInfo(mWifiInfo);
+        requestPolledInfo(mWifiInfo, false);
         return mWifiInfo;
     }
 
@@ -1331,9 +1331,10 @@ public class WifiStateTracker extends NetworkStateTracker {
      * Get the dynamic information that is not reported via events.
      * @param info the object into which the information should be captured.
      */
-    private synchronized void requestPolledInfo(WifiInfo info)
+    private synchronized void requestPolledInfo(WifiInfo info, boolean polling)
     {
-        int newRssi = WifiNative.getRssiCommand();
+        int newRssi = (polling ? WifiNative.getRssiApproxCommand():
+                                 WifiNative.getRssiCommand());
         if (newRssi != -1 && -200 < newRssi && newRssi < 100) { // screen out invalid values
             info.setRssi(newRssi);
             /*