Camera2: When focus is already locked in CAF mode, do not trigger HAL.

In HAL2 CAF modes, once focus is locked by an AF trigger, additional
triggers will not cause AF notifications, since the state will not
change again until a cancelAutofocus call.

Since the old API still expects to see a notification, short-circuit
this at the service and send an immediate success notification.

Bug: 7318298
Change-Id: Ib209a24eaf2a35a247d06aea671efe80a33d751e

3 files changed, 41 insertions, 4 deletions

diff --git a/services/camera/libcameraservice/Camera2Client.cpp b/services/camera/libcameraservice/Camera2Client.cpp
index 7290663..c5ea3ed 100644
--- a/services/camera/libcameraservice/Camera2Client.cpp
+++ b/services/camera/libcameraservice/Camera2Client.cpp
@@ -267,6 +267,17 @@ status_t Camera2Client::dump(int fd, const Vector<String16>& args) {
         default: result.append("UNKNOWN\n");
     }
 
+    result.append("   Focus state: ");
+    switch (p.focusState) {
+        CASE_APPEND_ENUM(ANDROID_CONTROL_AF_STATE_INACTIVE)
+        CASE_APPEND_ENUM(ANDROID_CONTROL_AF_STATE_PASSIVE_SCAN)
+        CASE_APPEND_ENUM(ANDROID_CONTROL_AF_STATE_PASSIVE_FOCUSED)
+        CASE_APPEND_ENUM(ANDROID_CONTROL_AF_STATE_ACTIVE_SCAN)
+        CASE_APPEND_ENUM(ANDROID_CONTROL_AF_STATE_FOCUSED_LOCKED)
+        CASE_APPEND_ENUM(ANDROID_CONTROL_AF_STATE_NOT_FOCUSED_LOCKED)
+        default: result.append("UNKNOWN\n");
+    }
+
     result.append("    Focusing areas:\n");
     for (size_t i = 0; i < p.focusingAreas.size(); i++) {
         result.appendFormat("      [ (%d, %d, %d, %d), weight %d ]\n",
@@ -952,6 +963,8 @@ status_t Camera2Client::autoFocus() {
     if ( (res = checkPid(__FUNCTION__) ) != OK) return res;
 
     int triggerId;
+    bool notifyImmediately = false;
+    bool notifySuccess = false;
     {
         SharedParameters::Lock l(mParameters);
         if (l.mParameters.state < Parameters::PREVIEW) {
@@ -964,15 +977,34 @@ status_t Camera2Client::autoFocus() {
           * with a fake value of success set to true.
           */
         if (l.mParameters.focusMode == Parameters::FOCUS_MODE_FIXED) {
+            notifyImmediately = true;
+            notifySuccess = true;
+        }
+        /**
+         * If we're in CAF mode, and AF has already been locked, just fire back
+         * the callback right away; the HAL would not send a notification since
+         * no state change would happen on a AF trigger.
+         */
+        if ( (l.mParameters.focusMode == Parameters::FOCUS_MODE_CONTINUOUS_PICTURE ||
+                l.mParameters.focusMode == Parameters::FOCUS_MODE_CONTINUOUS_VIDEO) &&
+                l.mParameters.focusState == ANDROID_CONTROL_AF_STATE_FOCUSED_LOCKED ) {
+            notifyImmediately = true;
+            notifySuccess = true;
+        }
+        /**
+         * Send immediate notification back to client
+         */
+        if (notifyImmediately) {
             SharedCameraClient::Lock l(mSharedCameraClient);
             if (l.mCameraClient != 0) {
                 l.mCameraClient->notifyCallback(CAMERA_MSG_FOCUS,
-                    /*success*/1, 0);
+                        notifySuccess ? 1 : 0, 0);
             }
-
             return OK;
         }
-
+        /**
+         * Handle quirk mode for AF in scene modes
+         */
         if (l.mParameters.quirks.triggerAfWithAuto &&
                 l.mParameters.sceneMode != ANDROID_CONTROL_SCENE_MODE_UNSUPPORTED &&
                 l.mParameters.focusMode != Parameters::FOCUS_MODE_AUTO) {
@@ -1303,6 +1335,7 @@ void Camera2Client::notifyAutoFocus(uint8_t newState, int triggerId) {
     bool afInMotion = false;
     {
         SharedParameters::Lock l(mParameters);
+        l.mParameters.focusState = newState;
         switch (l.mParameters.focusMode) {
             case Parameters::FOCUS_MODE_AUTO:
             case Parameters::FOCUS_MODE_MACRO:
diff --git a/services/camera/libcameraservice/camera2/Parameters.cpp b/services/camera/libcameraservice/camera2/Parameters.cpp
index 3c679da..9a0083a 100644
--- a/services/camera/libcameraservice/camera2/Parameters.cpp
+++ b/services/camera/libcameraservice/camera2/Parameters.cpp
@@ -633,6 +633,7 @@ status_t Parameters::initialize(const CameraMetadata *info) {
         params.set(CameraParameters::KEY_SUPPORTED_FOCUS_MODES,
                 supportedFocusModes);
     }
+    focusState = ANDROID_CONTROL_AF_STATE_INACTIVE;
     shadowFocusMode = FOCUS_MODE_INVALID;
 
     camera_metadata_ro_entry_t max3aRegions =
@@ -1462,8 +1463,9 @@ status_t Parameters::set(const String8& paramString) {
                 }
             }
         }
+        validatedParams.focusState = ANDROID_CONTROL_AF_STATE_INACTIVE;
         // Always reset shadow focus mode to avoid reverting settings
-        shadowFocusMode = FOCUS_MODE_INVALID;
+        validatedParams.shadowFocusMode = FOCUS_MODE_INVALID;
         // Update in case of override
         newParams.set(CameraParameters::KEY_FOCUS_MODE,
                 focusModeEnumToString(validatedParams.focusMode));
diff --git a/services/camera/libcameraservice/camera2/Parameters.h b/services/camera/libcameraservice/camera2/Parameters.h
index fd02744..8a8645e 100644
--- a/services/camera/libcameraservice/camera2/Parameters.h
+++ b/services/camera/libcameraservice/camera2/Parameters.h
@@ -88,6 +88,8 @@ struct Parameters {
         FOCUS_MODE_INVALID = -1
     } focusMode;
 
+    uint8_t focusState; // Latest focus state from HAL
+
     // For use with triggerAfWithAuto quirk
     focusMode_t shadowFocusMode;