From 8cece4f260d5f3db9a80946a53839d79398bda7b Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Fri, 15 Dec 2017 06:19:31 +0000
Subject: [PATCH] runtime: hotswap slightly more carefully.

This generally lets some last characters out of UART, last ACKs
out of queues, etc. Nothing guaranteed though.
---
 artiq/firmware/runtime/mgmt.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/artiq/firmware/runtime/mgmt.rs b/artiq/firmware/runtime/mgmt.rs
index 2078e2a3a..0cdb7eef6 100644
--- a/artiq/firmware/runtime/mgmt.rs
+++ b/artiq/firmware/runtime/mgmt.rs
@@ -82,9 +82,10 @@ fn worker(io: &Io, stream: &mut TcpStream) -> io::Result<()> {
             },
 
             Request::Hotswap(firmware) => {
+                warn!("hotswapping firmware");
                 Reply::RebootImminent.write_to(stream)?;
                 stream.close()?;
-                warn!("hotswapping firmware");
+                stream.flush()?;
                 unsafe { board::boot::hotswap(&firmware) }
             },