From 74fa8a3907359a7c7e9159601b8a8c2c6b79e960 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Fri, 9 Dec 2016 19:04:30 -0500
Subject: serialhdl: Clear "hupcl" bit from serial port

The arduino style serial port interfaces can reset the MCU when the
serial port is opened.  Clearing the HUPCL flag makes this less
likely.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 klippy/util.py | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'klippy/util.py')

diff --git a/klippy/util.py b/klippy/util.py
index caac827e..6bbfd9af 100644
--- a/klippy/util.py
+++ b/klippy/util.py
@@ -16,6 +16,12 @@ def set_nonblock(fd):
     fcntl.fcntl(fd, fcntl.F_SETFL
                 , fcntl.fcntl(fd, fcntl.F_GETFL) | os.O_NONBLOCK)
 
+# Clear HUPCL flag
+def clear_hupcl(fd):
+    attrs = termios.tcgetattr(fd)
+    attrs[2] = attrs[2] & ~termios.HUPCL
+    termios.tcsetattr(fd, termios.TCSADRAIN, attrs)
+
 # Support for creating a pseudo-tty for emulating a serial port
 def create_pty(ptyname):
     mfd, sfd = pty.openpty()
-- 
cgit v1.2.3-70-g09d2