4 files changed, 44 insertions, 17 deletions

diff --git a/src/core/hle/service/nvflinger/buffer_queue.cpp b/src/core/hle/service/nvflinger/buffer_queue.cpp
index 5731e815f..e1a07d3ee 100644
--- a/src/core/hle/service/nvflinger/buffer_queue.cpp
+++ b/src/core/hle/service/nvflinger/buffer_queue.cpp
@@ -34,7 +34,8 @@ void BufferQueue::SetPreallocatedBuffer(u32 slot, const IGBPBuffer& igbp_buffer)
     buffer_wait_event.writable->Signal();
 }
 
-std::optional<u32> BufferQueue::DequeueBuffer(u32 width, u32 height) {
+std::optional<std::pair<u32, Service::Nvidia::MultiFence*>> BufferQueue::DequeueBuffer(u32 width,
+                                                                                       u32 height) {
     auto itr = std::find_if(queue.begin(), queue.end(), [&](const Buffer& buffer) {
         // Only consider free buffers. Buffers become free once again after they've been Acquired
         // and Released by the compositor, see the NVFlinger::Compose method.
@@ -51,7 +52,7 @@ std::optional<u32> BufferQueue::DequeueBuffer(u32 width, u32 height) {
     }
 
     itr->status = Buffer::Status::Dequeued;
-    return itr->slot;
+    return {{itr->slot, &itr->multi_fence}};
 }
 
 const IGBPBuffer& BufferQueue::RequestBuffer(u32 slot) const {
@@ -63,7 +64,8 @@ const IGBPBuffer& BufferQueue::RequestBuffer(u32 slot) const {
 }
 
 void BufferQueue::QueueBuffer(u32 slot, BufferTransformFlags transform,
-                              const Common::Rectangle<int>& crop_rect) {
+                              const Common::Rectangle<int>& crop_rect, u32 swap_interval,
+                              Service::Nvidia::MultiFence& multi_fence) {
     auto itr = std::find_if(queue.begin(), queue.end(),
                             [&](const Buffer& buffer) { return buffer.slot == slot; });
     ASSERT(itr != queue.end());
@@ -71,12 +73,21 @@ void BufferQueue::QueueBuffer(u32 slot, BufferTransformFlags transform,
     itr->status = Buffer::Status::Queued;
     itr->transform = transform;
     itr->crop_rect = crop_rect;
+    itr->swap_interval = swap_interval;
+    itr->multi_fence = multi_fence;
+    queue_sequence.push_back(slot);
 }
 
 std::optional<std::reference_wrapper<const BufferQueue::Buffer>> BufferQueue::AcquireBuffer() {
-    auto itr = std::find_if(queue.begin(), queue.end(), [](const Buffer& buffer) {
-        return buffer.status == Buffer::Status::Queued;
-    });
+    auto itr = queue.end();
+    // Iterate to find a queued buffer matching the requested slot.
+    while (itr == queue.end() && !queue_sequence.empty()) {
+        u32 slot = queue_sequence.front();
+        itr = std::find_if(queue.begin(), queue.end(), [&slot](const Buffer& buffer) {
+            return buffer.status == Buffer::Status::Queued && buffer.slot == slot;
+        });
+        queue_sequence.pop_front();
+    }
     if (itr == queue.end())
         return {};
     itr->status = Buffer::Status::Acquired;
diff --git a/src/core/hle/service/nvflinger/buffer_queue.h b/src/core/hle/service/nvflinger/buffer_queue.h
index e1ccb6171..356bedb81 100644
--- a/src/core/hle/service/nvflinger/buffer_queue.h
+++ b/src/core/hle/service/nvflinger/buffer_queue.h
@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <list>
 #include <optional>
 #include <vector>
 
@@ -12,6 +13,7 @@
 #include "common/swap.h"
 #include "core/hle/kernel/object.h"
 #include "core/hle/kernel/writable_event.h"
+#include "core/hle/service/nvdrv/nvdata.h"
 
 namespace Service::NVFlinger {
 
@@ -68,13 +70,17 @@ public:
         IGBPBuffer igbp_buffer;
         BufferTransformFlags transform;
         Common::Rectangle<int> crop_rect;
+        u32 swap_interval;
+        Service::Nvidia::MultiFence multi_fence;
     };
 
     void SetPreallocatedBuffer(u32 slot, const IGBPBuffer& igbp_buffer);
-    std::optional<u32> DequeueBuffer(u32 width, u32 height);
+    std::optional<std::pair<u32, Service::Nvidia::MultiFence*>> DequeueBuffer(u32 width,
+                                                                              u32 height);
     const IGBPBuffer& RequestBuffer(u32 slot) const;
     void QueueBuffer(u32 slot, BufferTransformFlags transform,
-                     const Common::Rectangle<int>& crop_rect);
+                     const Common::Rectangle<int>& crop_rect, u32 swap_interval,
+                     Service::Nvidia::MultiFence& multi_fence);
     std::optional<std::reference_wrapper<const Buffer>> AcquireBuffer();
     void ReleaseBuffer(u32 slot);
     u32 Query(QueryType type);
@@ -92,6 +98,7 @@ private:
     u64 layer_id;
 
     std::vector<Buffer> queue;
+    std::list<u32> queue_sequence;
     Kernel::EventPair buffer_wait_event;
 };
 
diff --git a/src/core/hle/service/nvflinger/nvflinger.cpp b/src/core/hle/service/nvflinger/nvflinger.cpp
index 3c5c53e24..f9db79370 100644
--- a/src/core/hle/service/nvflinger/nvflinger.cpp
+++ b/src/core/hle/service/nvflinger/nvflinger.cpp
@@ -37,15 +37,14 @@ NVFlinger::NVFlinger(Core::Timing::CoreTiming& core_timing) : core_timing{core_t
     displays.emplace_back(4, "Null");
 
     // Schedule the screen composition events
-    const auto ticks = Settings::values.force_30fps_mode ? frame_ticks_30fps : frame_ticks;
-
-    composition_event = core_timing.RegisterEvent(
-        "ScreenComposition", [this, ticks](u64 userdata, s64 cycles_late) {
-            Compose();
-            this->core_timing.ScheduleEvent(ticks - cycles_late, composition_event);
-        });
-
-    core_timing.ScheduleEvent(ticks, composition_event);
+    composition_event = core_timing.RegisterEvent("ScreenComposition", [this](u64 userdata,
+                                                                              s64 cycles_late) {
+        Compose();
+        const auto ticks = Settings::values.force_30fps_mode ? frame_ticks_30fps : GetNextTicks();
+        this->core_timing.ScheduleEvent(std::max<s64>(0LL, ticks - cycles_late), composition_event);
+    });
+
+    core_timing.ScheduleEvent(frame_ticks, composition_event);
 }
 
 NVFlinger::~NVFlinger() {
@@ -206,8 +205,14 @@ void NVFlinger::Compose() {
                      igbp_buffer.width, igbp_buffer.height, igbp_buffer.stride,
                      buffer->get().transform, buffer->get().crop_rect);
 
+        swap_interval = buffer->get().swap_interval;
         buffer_queue.ReleaseBuffer(buffer->get().slot);
     }
 }
 
+s64 NVFlinger::GetNextTicks() const {
+    constexpr s64 max_hertz = 120LL;
+    return (Core::Timing::BASE_CLOCK_RATE * (1LL << swap_interval)) / max_hertz;
+}
+
 } // namespace Service::NVFlinger
diff --git a/src/core/hle/service/nvflinger/nvflinger.h b/src/core/hle/service/nvflinger/nvflinger.h
index c0a83fffb..988be8726 100644
--- a/src/core/hle/service/nvflinger/nvflinger.h
+++ b/src/core/hle/service/nvflinger/nvflinger.h
@@ -74,6 +74,8 @@ public:
     /// finished.
     void Compose();
 
+    s64 GetNextTicks() const;
+
 private:
     /// Finds the display identified by the specified ID.
     VI::Display* FindDisplay(u64 display_id);
@@ -98,6 +100,8 @@ private:
     /// layers.
     u32 next_buffer_queue_id = 1;
 
+    u32 swap_interval = 1;
+
     /// Event that handles screen composition.
     Core::Timing::EventType* composition_event;