From c09ce029dfafebb539944e71b8949c6179213f8f Mon Sep 17 00:00:00 2001
From: Stenzek <stenzek@gmail.com>
Date: Mon, 7 Nov 2016 19:22:27 +1000
Subject: [PATCH] Vulkan: Don't use FIFO_RELAXED present mode for vsync.

---
 .../Core/VideoBackends/Vulkan/SwapChain.cpp   | 24 +++++--------------
 1 file changed, 6 insertions(+), 18 deletions(-)

diff --git a/Source/Core/VideoBackends/Vulkan/SwapChain.cpp b/Source/Core/VideoBackends/Vulkan/SwapChain.cpp
index 899f931c6d..1027099d21 100644
--- a/Source/Core/VideoBackends/Vulkan/SwapChain.cpp
+++ b/Source/Core/VideoBackends/Vulkan/SwapChain.cpp
@@ -198,25 +198,13 @@ bool SwapChain::SelectPresentMode()
     return it != present_modes.end();
   };
 
-  // If vsync is enabled, prefer VK_PRESENT_MODE_FIFO_KHR.
-  if (m_vsync_enabled)
+  // If vsync is enabled, use VK_PRESENT_MODE_FIFO_KHR.
+  // This check should not fail with conforming drivers, as the FIFO present mode is mandated by
+  // the specification (VK_KHR_swapchain). In case it isn't though, fall through to any other mode.
+  if (m_vsync_enabled && CheckForMode(VK_PRESENT_MODE_FIFO_KHR))
   {
-    // Try for relaxed vsync first, since it's likely the VI won't line up with
-    // the refresh rate of the system exactly, so tearing once is better than
-    // waiting for the next vblank.
-    if (CheckForMode(VK_PRESENT_MODE_FIFO_RELAXED_KHR))
-    {
-      m_present_mode = VK_PRESENT_MODE_FIFO_RELAXED_KHR;
-      return true;
-    }
-
-    // Fall back to strict vsync.
-    if (CheckForMode(VK_PRESENT_MODE_FIFO_KHR))
-    {
-      WARN_LOG(VIDEO, "Vulkan: FIFO_RELAXED not available, falling back to FIFO.");
-      m_present_mode = VK_PRESENT_MODE_FIFO_KHR;
-      return true;
-    }
+    m_present_mode = VK_PRESENT_MODE_FIFO_KHR;
+    return true;
   }
 
   // Prefer screen-tearing, if possible, for lowest latency.