Merge "libvulkan: Un-revert and fix VK_PRESENT_MODE_MAILBOX_KHR" into nyc-dev
diff --git a/vulkan/libvulkan/swapchain.cpp b/vulkan/libvulkan/swapchain.cpp
index 3bd9db2..f9158a5 100644
--- a/vulkan/libvulkan/swapchain.cpp
+++ b/vulkan/libvulkan/swapchain.cpp
@@ -350,8 +350,10 @@
              "swapchain re-creation not yet implemented");
     ALOGE_IF(create_info->preTransform != VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR,
              "swapchain preTransform not yet implemented");
-    ALOGE_IF(create_info->presentMode != VK_PRESENT_MODE_FIFO_KHR,
-             "present modes other than FIFO are not yet implemented");
+    ALOGW_IF(!(create_info->presentMode == VK_PRESENT_MODE_FIFO_KHR ||
+               create_info->presentMode == VK_PRESENT_MODE_MAILBOX_KHR),
+             "swapchain present mode %d not supported",
+             create_info->presentMode);
 
     // -- Configure the native window --
 
@@ -390,6 +392,13 @@
         ALOGE("window->query failed: %s (%d)", strerror(-err), err);
         return VK_ERROR_INITIALIZATION_FAILED;
     }
+    // The MIN_UNDEQUEUED_BUFFERS query doesn't know whether we'll be using
+    // async mode or not, and assumes not. But in async mode, the BufferQueue
+    // requires an extra undequeued buffer.
+    // See BufferQueueCore::getMinUndequeuedBufferCountLocked().
+    if (create_info->presentMode == VK_PRESENT_MODE_MAILBOX_KHR)
+        min_undequeued_buffers += 1;
+
     uint32_t num_images =
         (create_info->minImageCount - 1) + min_undequeued_buffers;
     err = native_window_set_buffer_count(surface.window.get(), num_images);
@@ -422,6 +431,17 @@
         return VK_ERROR_INITIALIZATION_FAILED;
     }
 
+    err = surface.window->setSwapInterval(
+        surface.window.get(),
+        create_info->presentMode == VK_PRESENT_MODE_MAILBOX_KHR ? 0 : 1);
+    if (err != 0) {
+        // TODO(jessehall): Improve error reporting. Can we enumerate possible
+        // errors and translate them to valid Vulkan result codes?
+        ALOGE("native_window->setSwapInterval failed: %s (%d)", strerror(-err),
+              err);
+        return VK_ERROR_INITIALIZATION_FAILED;
+    }
+
     // -- Allocate our Swapchain object --
     // After this point, we must deallocate the swapchain on error.