From bb540df2d125475b0e864478c3336b0f9a422e4d Mon Sep 17 00:00:00 2001
From: Ron Evans <ron@hybridgroup.com>
Date: Mon, 13 Apr 2020 14:34:54 +0200
Subject: [PATCH] flash: retry 3 times when attempting to reset the serial port

Signed-off-by: Ron Evans <ron@hybridgroup.com>
---
 main.go | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/main.go b/main.go
index af9a7705..9af1a76d 100644
--- a/main.go
+++ b/main.go
@@ -473,16 +473,22 @@ func Run(pkgName string, options *compileopts.Options) error {
 	})
 }
 
-func touchSerialPortAt1200bps(port string) error {
-	// Open port
-	p, err := serial.Open(port, &serial.Mode{BaudRate: 1200})
-	if err != nil {
-		return fmt.Errorf("opening port: %s", err)
-	}
-	defer p.Close()
+func touchSerialPortAt1200bps(port string) (err error) {
+	retryCount := 3
+	for i := 0; i < retryCount; i++ {
+		// Open port
+		p, e := serial.Open(port, &serial.Mode{BaudRate: 1200})
+		if e != nil {
+			time.Sleep(1 * time.Second)
+			err = e
+			continue
+		}
+		defer p.Close()
 
-	p.SetDTR(false)
-	return nil
+		p.SetDTR(false)
+		return nil
+	}
+	return fmt.Errorf("opening port: %s", err)
 }
 
 func flashUF2UsingMSD(volume, tmppath string) error {