From c61e840391aea85ca58b4b1336b916decf9273ab Mon Sep 17 00:00:00 2001
From: Amar Shah <amar.shah@neuralink.com>
Date: Wed, 23 Jul 2025 15:36:25 -0700
Subject: [PATCH] Drop downstream data in rtt_server if no down channels

---
 pyocd/utility/rtt_server.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pyocd/utility/rtt_server.py b/pyocd/utility/rtt_server.py
index 43bfa65fd..94386374d 100644
--- a/pyocd/utility/rtt_server.py
+++ b/pyocd/utility/rtt_server.py
@@ -181,11 +181,12 @@ def poll(self):
             self.up_buffers[i] = self.up_buffers[i][bytes_written:]
 
             # Read from worker
-            self.down_buffers[i] += worker.get_down_data()
-
+            new_down_data = worker.get_down_data()
+            
             # Write data to down channel
             try:
                 down_chan: RTTDownChannel = self.control_block.down_channels[i]
+                self.down_buffers[i] += new_down_data
             except IndexError:
                 pass
             else: