commit 3cf4bfe2368020b50a3e22360910b6af6590c5be
author Dan Stoza <stoza@google.com> Tue Aug 02 10:27:31 2016 -0700
committer Dan Stoza <stoza@google.com> Wed Aug 10 12:56:46 2016 -0700
tree c10331f1f1eef193be7affd37d6f3f0c3d3b8c95
parent cf6e673296e8a3a7072f055770da59543935ae48

DO NOT MERGE SF: Add property to disable HWC virtual displays

Adds the property debug.sf.disable_hwc_vds, which will disable the use
of Hardware Composer virtual displays inside SurfaceFlinger (falling
back to SurfaceFlinger management and client composition of such
displays).

Also adds a Binder debug interface for controlling this behavior.

Bug: 30510632
Change-Id: I2c1a199213a24195b144bfa0c0f1679f2dfd0668

services/surfaceflinger/SurfaceFlinger_hwc1.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
index 34240b4..3a65e85 100644
--- a/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
+++ b/services/surfaceflinger/SurfaceFlinger_hwc1.cpp
@@ -181,6 +181,10 @@
     }
     ALOGI_IF(mDebugRegion, "showupdates enabled");
     ALOGI_IF(mDebugDDMS, "DDMS debugging enabled");
+
+    property_get("debug.sf.disable_hwc_vds", value, "0");
+    mUseHwcVirtualDisplays = !atoi(value);
+    ALOGI_IF(!mUseHwcVirtualDisplays, "Disabling HWC virtual displays");
 }
 
 void SurfaceFlinger::onFirstRef()
@@ -1508,9 +1512,10 @@
                                     NATIVE_WINDOW_HEIGHT, &height);
                             ALOGE_IF(status != NO_ERROR,
                                     "Unable to query height (%d)", status);
-                            if (MAX_VIRTUAL_DISPLAY_DIMENSION == 0 ||
+                            if (mUseHwcVirtualDisplays &&
+                                    (MAX_VIRTUAL_DISPLAY_DIMENSION == 0 ||
                                     (width <= MAX_VIRTUAL_DISPLAY_DIMENSION &&
-                                     height <= MAX_VIRTUAL_DISPLAY_DIMENSION)) {
+                                     height <= MAX_VIRTUAL_DISPLAY_DIMENSION))) {
                                 hwcDisplayId = allocateHwcDisplayId(state.type);
                             }
 
@@ -3191,6 +3196,11 @@
                 mSFEventThread->setPhaseOffset(static_cast<nsecs_t>(n));
                 return NO_ERROR;
             }
+            case 1021: { // Disable HWC virtual displays
+                n = data.readInt32();
+                mUseHwcVirtualDisplays = !n;
+                return NO_ERROR;
+            }
         }
     }
     return err;