Fixed headset detection broken on stingray

commit 5e64321 broke the headset detection on stingray.
This is because the name passed with the UEvent upon headset insertion/removal is
different from the dev path (h2w). It actually indicates the type of headset connected.

The fix consists in using the dev path received with the UEvent to find the corresponding
entry in uEventInfo.

Change-Id: I8481cfa17a7af3c8f5d83fc87d0f7c0d2c981098

Author: Eric Laurent

services/java/com/android/server/WiredAccessoryObserver.java

@@ -66,7 +66,7 @@ public UEventInfo(String devName, int state1Bits, int state2Bits) {
         public String getDevName() { return mDevName; }
 
         public String getDevPath() {
-            return String.format("DEVPATH=/devices/virtual/switch/%s", mDevName);
+            return String.format("/devices/virtual/switch/%s", mDevName);
         }
 
         public String getSwitchStatePath() {
@@ -158,7 +158,7 @@ public void onReceive(Context context, Intent intent) {
         init();  // set initial status
         for (int i = 0; i < uEventInfo.size(); ++i) {
             UEventInfo uei = uEventInfo.get(i);
-            startObserving(uei.getDevPath());
+            startObserving("DEVPATH="+uei.getDevPath());
         }
       }
     }
@@ -168,29 +168,20 @@ public void onUEvent(UEventObserver.UEvent event) {
         if (LOG) Slog.v(TAG, "Headset UEVENT: " + event.toString());
 
         try {
+            String devPath = event.get("DEVPATH");
             String name = event.get("SWITCH_NAME");
             int state = Integer.parseInt(event.get("SWITCH_STATE"));
-            updateState(name, state);
+            updateState(devPath, name, state);
         } catch (NumberFormatException e) {
             Slog.e(TAG, "Could not parse switch state from event " + event);
         }
     }
 
-    private synchronized final void updateState(String name, int state)
+    private synchronized final void updateState(String devPath, String name, int state)
     {
-        // FIXME:  When ueventd informs of a change in state for a switch, it does not have to be
-        // the case that the name reported by /sys/class/switch/<device>/name is the same as
-        // <device>.  For normal users of the linux switch class driver, it will be.  But it is
-        // technically possible to hook the print_name method in the class driver and return a
-        // different name each and every time the name sysfs entry is queried.
-        //
-        // Right now this is not the case for any of the switch implementations used here.  I'm not
-        // certain anyone would ever choose to implement such a dynamic name, or what it would mean
-        // for the implementation at this level, but if it ever happens, we will need to revisit
-        // this code.
         for (int i = 0; i < uEventInfo.size(); ++i) {
             UEventInfo uei = uEventInfo.get(i);
-            if (name.equals(uei.getDevName())) {
+            if (devPath.equals(uei.getDevPath())) {
                 update(name, uei.computeNewHeadsetState(mHeadsetState, state));
                 return;
             }
@@ -213,7 +204,7 @@ private synchronized final void init() {
                 curState = Integer.valueOf((new String(buffer, 0, len)).trim());
 
                 if (curState > 0) {
-                    updateState(uei.getDevName(), curState);
+                    updateState(uei.getDevPath(), uei.getDevName(), curState);
                 }
 
             } catch (FileNotFoundException e) {