From c73028bb1bfe1063e85041e648515fbdc800803c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Igor=20Mi=C5=A1i=C4=87?= <igy1000mb@gmail.com>
Date: Fri, 19 Nov 2021 15:08:55 +0100
Subject: [PATCH] iridiumsbd:  discard all pending data for flow control
 enabled

---
 src/drivers/telemetry/iridiumsbd/IridiumSBD.cpp | 12 +++++++++++-
 src/drivers/telemetry/iridiumsbd/IridiumSBD.h   |  1 +
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/drivers/telemetry/iridiumsbd/IridiumSBD.cpp b/src/drivers/telemetry/iridiumsbd/IridiumSBD.cpp
index 7b2760dc2a..95b72e4562 100644
--- a/src/drivers/telemetry/iridiumsbd/IridiumSBD.cpp
+++ b/src/drivers/telemetry/iridiumsbd/IridiumSBD.cpp
@@ -60,7 +60,7 @@ IridiumSBD::IridiumSBD()
 
 IridiumSBD::~IridiumSBD()
 {
-	::close(_uart_fd);
+	deinit();
 }
 
 int IridiumSBD::task_spawn(int argc, char *argv[])
@@ -214,6 +214,16 @@ int IridiumSBD::init(int argc, char *argv[])
 	return PX4_OK;
 }
 
+void IridiumSBD::deinit()
+{
+	if (_uart_fd >= 0) {
+		/* discard all pending data, as close() might block otherwise on NuttX with flow control enabled */
+		tcflush(_uart_fd, TCIOFLUSH);
+		::close(_uart_fd);
+		_uart_fd = -1;
+	}
+}
+
 int IridiumSBD::print_status()
 {
 	PX4_INFO("started");
diff --git a/src/drivers/telemetry/iridiumsbd/IridiumSBD.h b/src/drivers/telemetry/iridiumsbd/IridiumSBD.h
index 75fecba0fc..efc2a5cf47 100644
--- a/src/drivers/telemetry/iridiumsbd/IridiumSBD.h
+++ b/src/drivers/telemetry/iridiumsbd/IridiumSBD.h
@@ -141,6 +141,7 @@ public:
 
 private:
 	int init(int argc, char *argv[]);
+	void deinit();
 
 	/*
 	 * Loop executed while in SATCOM_STATE_STANDBY