From 52ddb0efd9acee395d3ab58e338ac03f4b61a4e5 Mon Sep 17 00:00:00 2001
From: TheLastRar <TheLastRar@users.noreply.github.com>
Date: Sat, 6 Apr 2024 20:41:51 +0100
Subject: [PATCH] DEV9: Increase allowed number of to be ACKed tcp packets

---
 pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.cpp    | 5 +++++
 pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.h      | 1 +
 pcsx2/DEV9/Sessions/TCP_Session/TCP_Session_In.cpp | 5 +++--
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.cpp b/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.cpp
index f86d2c3cd2..2a08eae80d 100644
--- a/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.cpp
+++ b/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.cpp
@@ -55,6 +55,11 @@ namespace Sessions
 		std::lock_guard numberlock(myNumberSentry);
 		return GetDelta(_MySequenceNumber, _ReceivedAckNumber);
 	}
+	bool TCP_Session::ShouldWaitForAck()
+	{
+		std::lock_guard numberlock(myNumberSentry);
+		return _OldMyNumbers[0] == _ReceivedAckNumber;
+	}
 	std::tuple<u32, std::vector<u32>> TCP_Session::GetAllMyNumbers()
 	{
 		std::lock_guard numberlock(myNumberSentry);
diff --git a/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.h b/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.h
index 800466d219..09109af5c8 100644
--- a/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.h
+++ b/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session.h
@@ -93,6 +93,7 @@ namespace Sessions
 		void UpdateReceivedAckNumber(u32 ack);
 		u32 GetMyNumber();
 		u32 GetOutstandingSequenceLength();
+		bool ShouldWaitForAck();
 		std::tuple<u32, std::vector<u32>> GetAllMyNumbers();
 		void ResetMyNumbers();
 
diff --git a/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session_In.cpp b/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session_In.cpp
index fde4339d29..8a8eeb50c5 100644
--- a/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session_In.cpp
+++ b/pcsx2/DEV9/Sessions/TCP_Session/TCP_Session_In.cpp
@@ -67,6 +67,8 @@ namespace Sessions
 				return nullptr;
 		}
 
+		if (ShouldWaitForAck())
+			return nullptr;
 
 		//Note, windowSize will be updated before _ReceivedAckNumber, potential race condition
 		//in practice, we just get a smaller or -ve maxSize
@@ -78,8 +80,7 @@ namespace Sessions
 		else
 			maxSize = std::min<int>(maxSegmentSize, windowSize.load() - outstanding);
 
-		if (maxSize > 0 &&
-			myNumberACKed.load())
+		if (maxSize > 0)
 		{
 			std::unique_ptr<u8[]> buffer;
 			int err = 0;