Fix sys_io thread deadlock

Co-Authored-By: Megamouse <23019877+Megamouse@users.noreply.github.com>

rpcs3/Emu/Cell/Modules/cellPad.cpp

@@ -75,25 +75,35 @@ void pad_info::save(utils::serial& ar)
 
 extern void send_sys_io_connect_event(usz index, u32 state);
 
-void cellPad_NotifyStateChange(usz index, u64 /*state*/, bool locked)
+bool cellPad_NotifyStateChange(usz index, u64 /*state*/, bool locked, bool is_blocking = true)
 {
 	auto info = g_fxo->try_get<pad_info>();
 
 	if (!info)
 	{
-		return;
+		return true;
 	}
 
 	std::unique_lock lock(pad::g_pad_mutex, std::defer_lock);
 
 	if (locked)
 	{
-		lock.lock();
+		if (is_blocking)
+		{
+			lock.lock();
+		}
+		else
+		{
+			if (!lock.try_lock())
+			{
+				return false;
+			}
+		}
 	}
 
 	if (index >= info->get_max_connect())
 	{
-		return;
+		return true;
 	}
 
 	const auto handler = pad::get_current_handler();
@@ -102,7 +112,7 @@ void cellPad_NotifyStateChange(usz index, u64 /*state*/, bool locked)
 
 	if (pad->is_fake_pad)
 	{
-		return;
+		return true;
 	}
 
 	pad_data_internal& reported_info = info->reported_info[index];
@@ -117,7 +127,7 @@ void cellPad_NotifyStateChange(usz index, u64 /*state*/, bool locked)
 	if (~(old_status ^ new_status) & CELL_PAD_STATUS_CONNECTED)
 	{
 		// old and new have the same connection status
-		return;
+		return true;
 	}
 
 	reported_info.port_status = new_status | CELL_PAD_STATUS_ASSIGN_CHANGES;
@@ -139,6 +149,8 @@ void cellPad_NotifyStateChange(usz index, u64 /*state*/, bool locked)
 		reported_info.vendor_id = pad->m_vendor_id;
 		reported_info.product_id = pad->m_product_id;
 	}
+
+	return true;
 }
 
 extern void pad_state_notify_state_change(usz index, u32 state)

rpcs3/Emu/Cell/Modules/sys_io_.cpp

@@ -36,10 +36,12 @@ extern void sys_io_serialize(utils::serial& ar)
 	ensure(g_fxo->try_get<libio_sys_config>())->save_or_load(ar);
 }
 
-extern void cellPad_NotifyStateChange(usz index, u64 state, bool lock = true);
+extern bool cellPad_NotifyStateChange(usz index, u64 state, bool lock = true, bool is_blocking = true);
 
 void config_event_entry(ppu_thread& ppu)
 {
+	ppu.state += cpu_flag::wait;
+
 	auto& cfg = *ensure(g_fxo->try_get<libio_sys_config>());
 
 	if (!ppu.loaded_from_savestate)
@@ -48,7 +50,10 @@ void config_event_entry(ppu_thread& ppu)
 		ppu.check_state();
 	}
 
-	while (!sys_event_queue_receive(ppu, cfg.queue_id, vm::null, 0))
+	const u32 queue_id = cfg.queue_id;
+	auto queue = idm::get<lv2_obj, lv2_event_queue>(queue_id);
+
+	while (queue && sys_event_queue_receive(ppu, queue_id, vm::null, 0) == CELL_OK)
 	{
 		if (ppu.is_stopped())
 		{
@@ -61,6 +66,7 @@ void config_event_entry(ppu_thread& ppu)
 
 		// Wakeup
 		ppu.check_state();
+		ppu.state += cpu_flag::wait;
 
 		const u64 arg1 = ppu.gpr[5];
 		const u64 arg2 = ppu.gpr[6];
@@ -70,7 +76,17 @@ void config_event_entry(ppu_thread& ppu)
 
 		if (arg1 == 1)
 		{
-			cellPad_NotifyStateChange(arg2, arg3);
+			while (!cellPad_NotifyStateChange(arg2, arg3, false))
+			{
+				if (!queue->exists)
+				{
+					// Exit condition
+					queue = nullptr;
+					break;
+				}
+
+				thread_ctrl::wait_for(100);
+			}
 		}
 	}