patches/frameworks/av/0006-CameraService-Support-calling-addStates-in-enumerate.patch

From b08e3e719c2401cd4ed9c0c9e639f3f539425918 Mon Sep 17 00:00:00 2001
From: Artem Borisov <dedsa2002@gmail.com>
Date: Tue, 25 Sep 2018 12:39:22 +0300
Subject: [PATCH 6/6] CameraService: Support calling addStates in
 enumerateProviders

Some pre-P camera HALs trigger onDeviceStatusChange callback during HAL init.
This is horribly wrong and causes a race condition between enumerateProviders
and onDeviceStatusChange. While it wasn't really harmful in O, in P call sequence
was changed and now this race condition leads to two problems: null pointer dereference
in addStates because mFlashlight is not initialized at a proper timing; mServiceLock
deadlock because updateCameraNumAndIds and enumerateProviders are called at the same time.
Moving addStates back to enumerateProviders makes the sequence more similar to O, and doesn't
let these two issues to happen.
Enable TARGET_CAMERA_NEEDS_ADD_STATES_IN_ENUMERATE when it is necessary.

@Dil3mm4 edit: Instead of TARGET_CAMERA_NEEDS_ADD_STATES_IN_ENUMERATE let's use a system property to make it more generic and suitable for GSI use.

Change-Id: Ife25b9753fdb679ab0c77f385e1b8527551a4711
---
 .../camera/libcameraservice/CameraService.cpp   | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/services/camera/libcameraservice/CameraService.cpp b/services/camera/libcameraservice/CameraService.cpp
index 157f769a3..208b27051 100644
--- a/services/camera/libcameraservice/CameraService.cpp
+++ b/services/camera/libcameraservice/CameraService.cpp
@@ -181,6 +181,21 @@ status_t CameraService::enumerateProviders() {
 
     for (auto& cameraId : deviceIds) {
         String8 id8 = String8(cameraId.c_str());
+
+    if (property_get_bool("persist.sys.camera.huawei", false)) {
+        bool cameraFound = false;
+        {
+            Mutex::Autolock lock(mCameraStatesLock);
+            auto iter = mCameraStates.find(id8);
+            if (iter != mCameraStates.end()) {
+                cameraFound = true;
+            }
+        }
+        if (!cameraFound) {
+            addStates(id8);
+        }
+    }
+
         onDeviceStatusChanged(id8, CameraDeviceStatus::PRESENT);
     }
 
@@ -279,8 +294,10 @@ void CameraService::onDeviceStatusChanged(const String8& id,
             ALOGI("%s: Unknown camera ID %s, a new camera is added",
                     __FUNCTION__, id.string());
 
+   if (!property_get_bool("persist.sys.camera.huawei", false)) {
             // First add as absent to make sure clients are notified below
             addStates(id);
+   }
 
             updateStatus(newStatus, id);
         } else {
-- 
2.17.1