graphics: stall waitUntilSafeForRendering in its command processor instead of the GPU thread

src/graphics/guest_gpu/graphicsRun.cpp

@@ -30,6 +30,7 @@
 #include <mutex>
 #include <semaphore>
 #include <thread>
+#include <utility>
 #include <vector>
 
 namespace Libs::Graphics {
@@ -91,6 +92,12 @@ void GuestGpu::SendCommand(Common::UniqueFunction<void>&& command) {
 	m_work_available.Signal();
 }
 
+void GuestGpu::Wake() {
+	Common::LockGuard lock(m_queue_mutex);
+	m_wake_pending = true;
+	m_work_available.Signal();
+}
+
 void GuestGpu::ProcessCommands() {
 	EXIT_IF(!IsGpuThread());
 	while (m_pending_commands.load(std::memory_order_acquire) != 0) {
@@ -464,7 +471,10 @@ void GuestGpu::ThreadRun(void* data) {
 				}
 				if (selected_queue < 0) {
 					gpu->m_processing = false;
-					gpu->m_work_available.WaitFor(&gpu->m_queue_mutex, 100);
+					// A wake that came before this wait must not be lost.
+					if (!std::exchange(gpu->m_wake_pending, false)) {
+						gpu->m_work_available.WaitFor(&gpu->m_queue_mutex, 100);
+					}
 					for (auto& queue: gpu->m_queues) {
 						if (!queue.empty()) {
 							queue.front().blocked = false;
@@ -998,10 +1008,11 @@ void CommandProcessor::DrawIndexAuto(DrawAutoArgs args) {
 }
 
 void CommandProcessor::WaitFlipDone(uint32_t video_out_handle, uint32_t display_buffer_index) {
-	BufferFlush();
-
-	m_renderer.GetVideoOut().WaitFlipDone(static_cast<int>(video_out_handle),
-	                                      static_cast<int>(display_buffer_index));
+	// The SDK stalls only this command processor, not the host command lane or other queues.
+	if (!m_renderer.GetVideoOut().IsSafeForRendering(static_cast<int>(video_out_handle),
+	                                                 static_cast<int>(display_buffer_index))) {
+		SuspendPm4();
+	}
 }
 
 template <typename T>