From 24493a5fc1fbf6b3579c6a5732fd8c885d0483b1 Mon Sep 17 00:00:00 2001
From: "tim.cho" <tim.cho@amlogic.com>
Date: Thu, 28 Dec 2023 11:47:35 +0900
Subject: [PATCH] Subject: [PATCH] hwc: fix race condition issue when mcrtc be
 reset addition  [1/1]

PD#OTT-52909

Problem:
mcrtc be used After it be reset

Solution:
Add lock to protect the operation

Verify:
805C2
---
 hwcomposer/common/hwc/HwcVsync.cpp | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/hwcomposer/common/hwc/HwcVsync.cpp b/hwcomposer/common/hwc/HwcVsync.cpp
index 9449f33..8470506 100755
--- a/hwcomposer/common/hwc/HwcVsync.cpp
+++ b/hwcomposer/common/hwc/HwcVsync.cpp
@@ -208,14 +208,20 @@ int32_t HwcVsync::waitVsync(nsecs_t& vsync_timestamp, nsecs_t& period) {
 
 int32_t HwcVsync::waitHwVsync(nsecs_t& vsync_timestamp) {
     ATRACE_CALL();
-
     std::unique_lock<std::mutex> stateLock(mStatLock);
     if (!mCrtc.get()) {
         return -EFAULT;
     }
+    std::shared_ptr<HwDisplayCrtc> localCrtc = mCrtc;
+    stateLock.unlock();
+
+    int32_t ret = localCrtc->waitVBlank(mVsyncTime);
 
-    int32_t ret = mCrtc->waitVBlank(mVsyncTime);
+    stateLock.lock();
     vsync_timestamp = mVsyncTime;
+    localCrtc.reset();
+    stateLock.unlock();
+
     return ret;
 }
 
@@ -269,10 +275,19 @@ int32_t HwcVsync::waitMixVsync(nsecs_t& vsync_timestamp) {
         std::unique_lock<std::mutex> stateLock(mStatLock);
         if (!mCrtc.get())
             return -EFAULT;
-        mCrtc->waitVBlank(mVsyncTime);
+
+        std::shared_ptr<HwDisplayCrtc> localCrtc = mCrtc;
+        stateLock.unlock();
+
+        localCrtc->waitVBlank(mVsyncTime);
+
+        stateLock.lock();
         mVsyncTime += mMixOffset;
         cur_vsync_period = mReqPeriod;
         mMixRebase = false;
+
+        localCrtc.reset();
+        stateLock.unlock();
     } else {
         nsecs_t now = systemTime(CLOCK_MONOTONIC);
         mVsyncTime = mVsyncTime + cur_vsync_period +
-- 
2.17.1