8 files changed, 38 insertions, 21 deletions

diff --git a/src/core/hle/service/nvdrv/devices/nvdisp_disp0.cpp b/src/core/hle/service/nvdrv/devices/nvdisp_disp0.cpp
index c918b4225..76494f0b7 100644
--- a/src/core/hle/service/nvdrv/devices/nvdisp_disp0.cpp
+++ b/src/core/hle/service/nvdrv/devices/nvdisp_disp0.cpp
@@ -36,9 +36,8 @@ void nvdisp_disp0::flip(u32 buffer_handle, u32 offset, u32 format, u32 width, u3
         addr,      offset,   width, height, stride, static_cast<PixelFormat>(format),
         transform, crop_rect};
 
-    auto& instance = system;
-    instance.GetPerfStats().EndGameFrame();
-    instance.GPU().SwapBuffers(framebuffer);
+    system.GetPerfStats().EndGameFrame();
+    system.GPU().SwapBuffers(framebuffer);
 }
 
 } // namespace Service::Nvidia::Devices
diff --git a/src/core/hle/service/nvdrv/devices/nvhost_ctrl.cpp b/src/core/hle/service/nvdrv/devices/nvhost_ctrl.cpp
index 749aa71d4..1f178d17d 100644
--- a/src/core/hle/service/nvdrv/devices/nvhost_ctrl.cpp
+++ b/src/core/hle/service/nvdrv/devices/nvhost_ctrl.cpp
@@ -87,13 +87,19 @@ u32 nvhost_ctrl::IocCtrlEventWait(const std::vector<u8>& input, std::vector<u8>&
     u32 event_id;
     if (is_async) {
         event_id = params.value & 0x00FF;
-        if (event_id >= 64) {
+        if (event_id >= MaxNvEvents) {
             std::memcpy(output.data(), &params, sizeof(params));
             return NvResult::BadParameter;
         }
     } else {
         if (ctrl.fresh_call) {
-            event_id = events_interface.GetFreeEvent();
+            const auto result = events_interface.GetFreeEvent();
+            if (result) {
+                event_id = *result;
+            } else {
+                LOG_CRITICAL(Service_NVDRV, "No Free Events available!");
+                event_id = params.value & 0x00FF;
+            }
         } else {
             event_id = ctrl.event_id;
         }
@@ -129,6 +135,7 @@ u32 nvhost_ctrl::IocCtrlEventRegister(const std::vector<u8>& input, std::vector<
     IocCtrlEventRegisterParams params{};
     std::memcpy(&params, input.data(), sizeof(params));
     const u32 event_id = params.user_event_id & 0x00FF;
+    LOG_DEBUG(Service_NVDRV, " called, user_event_id: {:X}", event_id);
     if (event_id >= MaxNvEvents) {
         return NvResult::BadParameter;
     }
@@ -143,6 +150,7 @@ u32 nvhost_ctrl::IocCtrlEventUnregister(const std::vector<u8>& input, std::vecto
     IocCtrlEventUnregisterParams params{};
     std::memcpy(&params, input.data(), sizeof(params));
     const u32 event_id = params.user_event_id & 0x00FF;
+    LOG_DEBUG(Service_NVDRV, " called, user_event_id: {:X}", event_id);
     if (event_id >= MaxNvEvents) {
         return NvResult::BadParameter;
     }
@@ -159,7 +167,7 @@ u32 nvhost_ctrl::IocCtrlEventSignal(const std::vector<u8>& input, std::vector<u8
     // TODO(Blinkhawk): This is normally called when an NvEvents timeout on WaitSynchronization
     // It is believed from RE to cancel the GPU Event. However, better research is required
     u32 event_id = params.user_event_id & 0x00FF;
-    LOG_WARNING(Service_NVDRV, "(STUBBED) called, user_event_id: {:X}", event_id);
+    LOG_DEBUG(Service_NVDRV, " called, user_event_id: {:X}", event_id);
     if (event_id >= MaxNvEvents) {
         return NvResult::BadParameter;
     }
diff --git a/src/core/hle/service/nvdrv/devices/nvhost_gpu.h b/src/core/hle/service/nvdrv/devices/nvhost_gpu.h
index 3ad8e1db1..d2e8fbae9 100644
--- a/src/core/hle/service/nvdrv/devices/nvhost_gpu.h
+++ b/src/core/hle/service/nvdrv/devices/nvhost_gpu.h
@@ -10,6 +10,7 @@
 #include "common/common_types.h"
 #include "common/swap.h"
 #include "core/hle/service/nvdrv/devices/nvdevice.h"
+#include "core/hle/service/nvdrv/nvdata.h"
 
 namespace Service::Nvidia::Devices {
 
@@ -114,10 +115,6 @@ private:
     static_assert(sizeof(IoctlGetErrorNotification) == 16,
                   "IoctlGetErrorNotification is incorrect size");
 
-    struct Fence {
-        u32_le id;
-        u32_le value;
-    };
     static_assert(sizeof(Fence) == 8, "Fence is incorrect size");
 
     struct IoctlAllocGpfifoEx {
diff --git a/src/core/hle/service/nvdrv/interface.cpp b/src/core/hle/service/nvdrv/interface.cpp
index 6f7c7502a..b8877b6cb 100644
--- a/src/core/hle/service/nvdrv/interface.cpp
+++ b/src/core/hle/service/nvdrv/interface.cpp
@@ -103,7 +103,7 @@ void NVDRV::QueryEvent(Kernel::HLERequestContext& ctx) {
 
     IPC::ResponseBuilder rb{ctx, 3, 1};
     rb.Push(RESULT_SUCCESS);
-    if (event_id < 64) {
+    if (event_id < MaxNvEvents) {
         rb.PushCopyObjects(nvdrv->GetEvent(event_id));
         rb.Push<u32>(NvResult::Success);
     } else {
diff --git a/src/core/hle/service/nvdrv/nvdata.h b/src/core/hle/service/nvdrv/nvdata.h
index 22b1dc79b..ac03cbc23 100644
--- a/src/core/hle/service/nvdrv/nvdata.h
+++ b/src/core/hle/service/nvdrv/nvdata.h
@@ -35,9 +35,13 @@ enum class EventState {
 };
 
 struct IoctlCtrl {
+    // First call done to the servioce for services that call itself again after a call.
     bool fresh_call{true};
+    // Tells the Ioctl Wrapper that it must delay the IPC response and send the thread to sleep
     bool must_delay{};
+    // Timeout for the delay
     s64 timeout{};
+    // NV Event Id
     s32 event_id{-1};
 };
 
diff --git a/src/core/hle/service/nvdrv/nvdrv.h b/src/core/hle/service/nvdrv/nvdrv.h
index 8f7c59a21..a339ab672 100644
--- a/src/core/hle/service/nvdrv/nvdrv.h
+++ b/src/core/hle/service/nvdrv/nvdrv.h
@@ -27,25 +27,34 @@ class nvdevice;
 }
 
 struct EventInterface {
+    // Mask representing currently busy events
     u64 events_mask{};
+    // Each kernel event associated to an NV event
     std::array<Kernel::EventPair, MaxNvEvents> events;
+    // The status of the current NVEvent
     std::array<EventState, MaxNvEvents> status{};
+    // Tells if an NVEvent is registered or not
     std::array<bool, MaxNvEvents> registered{};
+    // When an NVEvent is waiting on GPU interrupt, this is the sync_point
+    // associated with it.
     std::array<u32, MaxNvEvents> assigned_syncpt{};
+    // This is the value of the GPU interrupt for which the NVEvent is waiting
+    // for.
     std::array<u32, MaxNvEvents> assigned_value{};
-    static constexpr u32 null_event = 0xFFFFFFFF;
-    u32 GetFreeEvent() const {
+    // Constant to denote an unasigned syncpoint.
+    static constexpr u32 unassigned_syncpt = 0xFFFFFFFF;
+    std::optional<u32> GetFreeEvent() const {
         u64 mask = events_mask;
         for (u32 i = 0; i < MaxNvEvents; i++) {
             const bool is_free = (mask & 0x1) == 0;
             if (is_free) {
                 if (status[i] == EventState::Registered || status[i] == EventState::Free) {
-                    return i;
+                    return {i};
                 }
             }
             mask = mask >> 1;
         }
-        return null_event;
+        return {};
     }
     void SetEventStatus(const u32 event_id, EventState new_status) {
         EventState old_status = status[event_id];
@@ -57,7 +66,7 @@ struct EventInterface {
             registered[event_id] = true;
         }
         if (new_status == EventState::Waiting || new_status == EventState::Busy) {
-            events_mask |= (1 << event_id);
+            events_mask |= (1ULL << event_id);
         }
     }
     void RegisterEvent(const u32 event_id) {
@@ -74,8 +83,8 @@ struct EventInterface {
     }
     void LiberateEvent(const u32 event_id) {
         status[event_id] = registered[event_id] ? EventState::Registered : EventState::Free;
-        events_mask &= ~(1 << event_id);
-        assigned_syncpt[event_id] = 0xFFFFFFFF;
+        events_mask &= ~(1ULL << event_id);
+        assigned_syncpt[event_id] = unassigned_syncpt;
         assigned_value[event_id] = 0;
     }
 };
diff --git a/src/core/hle/service/nvflinger/buffer_queue.cpp b/src/core/hle/service/nvflinger/buffer_queue.cpp
index ddc224f2c..e1a07d3ee 100644
--- a/src/core/hle/service/nvflinger/buffer_queue.cpp
+++ b/src/core/hle/service/nvflinger/buffer_queue.cpp
@@ -80,6 +80,7 @@ void BufferQueue::QueueBuffer(u32 slot, BufferTransformFlags transform,
 
 std::optional<std::reference_wrapper<const BufferQueue::Buffer>> BufferQueue::AcquireBuffer() {
     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) {
diff --git a/src/core/hle/service/vi/vi.cpp b/src/core/hle/service/vi/vi.cpp
index 894bcdc04..199b30635 100644
--- a/src/core/hle/service/vi/vi.cpp
+++ b/src/core/hle/service/vi/vi.cpp
@@ -536,7 +536,7 @@ private:
 
             if (result) {
                 // Buffer is available
-                IGBPDequeueBufferResponseParcel response{(*result).first, *(*result).second};
+                IGBPDequeueBufferResponseParcel response{result->first, *result->second};
                 ctx.WriteBuffer(response.Serialize());
             } else {
                 // Wait the current thread until a buffer becomes available
@@ -549,8 +549,7 @@ private:
                         auto result = buffer_queue.DequeueBuffer(width, height);
                         ASSERT_MSG(result != std::nullopt, "Could not dequeue buffer.");
 
-                        IGBPDequeueBufferResponseParcel response{(*result).first,
-                                                                 *(*result).second};
+                        IGBPDequeueBufferResponseParcel response{result->first, *result->second};
                         ctx.WriteBuffer(response.Serialize());
                         IPC::ResponseBuilder rb{ctx, 2};
                         rb.Push(RESULT_SUCCESS);