From de14b5cd04fd9fbbb1efa62a0a910644a403faa3 Mon Sep 17 00:00:00 2001
From: IP Susila <susila.ip@gmail.com>
Date: Wed, 23 Aug 2017 13:52:09 +0700
Subject: [PATCH] Fix issue #48 (errno 0),
 https://github.com/tarm/serial/issues/48

---
 serial_linux.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/serial_linux.go b/serial_linux.go
index adf18c6..afb3240 100644
--- a/serial_linux.go
+++ b/serial_linux.go
@@ -143,13 +143,17 @@ func (p *Port) Write(b []byte) (n int, err error) {
 // or data received but not read
 func (p *Port) Flush() error {
 	const TCFLSH = 0x540B
-	_, _, err := syscall.Syscall(
+	_, _, errno := syscall.Syscall(
 		syscall.SYS_IOCTL,
 		uintptr(p.f.Fd()),
 		uintptr(TCFLSH),
 		uintptr(syscall.TCIOFLUSH),
 	)
-	return err
+
+	if errno == 0 {
+		return nil
+	}
+	return errno
 }
 
 func (p *Port) Close() (err error) {