From 620685c2e684082c82657732d1e35cefd0c79006 Mon Sep 17 00:00:00 2001
From: Andy McFadden <fadden@android.com>
Date: Fri, 19 Oct 2012 12:53:46 -0700
Subject: [PATCH] Fix emulator vsync

The code that reserves display IDs was only run when a hardware
composer was present.  The eventControl() function, which handles
enabling of vsync, was ignoring the request because the primary
display didn't appear in its set of allocated IDs.  This moves
reservation of IDs for built-in displays outside the HWC-only block.

Also, added a couple of warnings in eventControl().

Bug 7376568

Change-Id: I185ccdf817a25499b5c2668f8f6d594afb8c1568
---
 .../DisplayHardware/HWComposer.cpp              | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index d9bda11fc..31d731eae 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -128,6 +128,11 @@ HWComposer::HWComposer(
         abort();
     }
 
+    // these display IDs are always reserved
+    for (size_t i=0 ; i<HWC_NUM_DISPLAY_TYPES ; i++) {
+        mAllocatedDisplayIDs.markBit(i);
+    }
+
     if (mHwc) {
         ALOGI("Using %s version %u.%u", HWC_HARDWARE_COMPOSER,
               (hwcApiVersion(mHwc) >> 24) & 0xff,
@@ -149,11 +154,6 @@ HWComposer::HWComposer(
         // always turn vsync off when we start
         eventControl(HWC_DISPLAY_PRIMARY, HWC_EVENT_VSYNC, 0);
 
-        // these IDs are always reserved
-        for (size_t i=0 ; i<HWC_NUM_DISPLAY_TYPES ; i++) {
-            mAllocatedDisplayIDs.markBit(i);
-        }
-
         // the number of displays we actually have depends on the
         // hw composer version
         if (hwcHasApiVersion(mHwc, HWC_DEVICE_API_VERSION_1_2)) {
@@ -445,6 +445,13 @@ bool HWComposer::isConnected(int disp) const {
 
 void HWComposer::eventControl(int disp, int event, int enabled) {
     if (uint32_t(disp)>31 || !mAllocatedDisplayIDs.hasBit(disp)) {
+        ALOGD("eventControl ignoring event %d on unallocated disp %d (en=%d)",
+              event, disp, enabled);
+        return;
+    }
+    if (event != EVENT_VSYNC) {
+        ALOGW("eventControl got unexpected event %d (disp=%d en=%d)",
+              event, disp, enabled);
         return;
     }
     status_t err = NO_ERROR;