Don't run large virtual displays through HWC

This change watches for a MAX_VIRTUAL_DISPLAY_DIMENSION value, which
will be set (if necessary) in BoardConfig.mk. If the value is set,
any virtual displays that have a width or a height greater than that
dimension will bypass the hardware composer HAL and be handled only
by SurfaceFlinger.

Bug: 17701816
Change-Id: Ia6ca44dfd6a7a9bc0f054493d3f13006bc32fa14

diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 57e94ef..76545f3 100644 (file)
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -83,6 +83,12 @@ else
     LOCAL_CFLAGS += -DPRESENT_TIME_OFFSET_FROM_VSYNC_NS=0
 endif
 
+ifneq ($(MAX_VIRTUAL_DISPLAY_DIMENSION),)
+    LOCAL_CFLAGS += -DMAX_VIRTUAL_DISPLAY_DIMENSION=$(MAX_VIRTUAL_DISPLAY_DIMENSION)
+else
+    LOCAL_CFLAGS += -DMAX_VIRTUAL_DISPLAY_DIMENSION=0
+endif
+
 LOCAL_CFLAGS += -fvisibility=hidden -Werror=format
 LOCAL_CFLAGS += -std=c++11
 

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 50968e7..17e984a 100644 (file)
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1328,7 +1328,22 @@ void SurfaceFlinger::handleTransactionLocked(uint32_t transactionFlags)
                         // etc.) but no internal state (i.e. a DisplayDevice).
                         if (state.surface != NULL) {
 
-                            hwcDisplayId = allocateHwcDisplayId(state.type);
+                            int width = 0;
+                            int status = state.surface->query(
+                                    NATIVE_WINDOW_WIDTH, &width);
+                            ALOGE_IF(status != NO_ERROR,
+                                    "Unable to query width (%d)", status);
+                            int height = 0;
+                            status = state.surface->query(
+                                    NATIVE_WINDOW_HEIGHT, &height);
+                            ALOGE_IF(status != NO_ERROR,
+                                    "Unable to query height (%d)", status);
+                            if (MAX_VIRTUAL_DISPLAY_DIMENSION == 0 ||
+                                    (width <= MAX_VIRTUAL_DISPLAY_DIMENSION &&
+                                     height <= MAX_VIRTUAL_DISPLAY_DIMENSION)) {
+                                hwcDisplayId = allocateHwcDisplayId(state.type);
+                            }
+
                             sp<VirtualDisplaySurface> vds = new VirtualDisplaySurface(
                                     *mHwc, hwcDisplayId, state.surface,
                                     bqProducer, bqConsumer, state.displayName);