From b8ed17b9dad515309f59154fb3c0e0a99fbbf6ac Mon Sep 17 00:00:00 2001
From: Xiang Xiao <xiaoxiang@xiaomi.com>
Date: Fri, 7 May 2021 00:39:08 -0700
Subject: [PATCH] libc/termios: Implement TCSADRAIN and TCSAFLUSH for tcsetattr

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: If87a4931cd5a55e064f58c19a22c7ce13f538000
---
 libs/libc/termios/lib_tcsetattr.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/libs/libc/termios/lib_tcsetattr.c b/libs/libc/termios/lib_tcsetattr.c
index e93bf584ea..cde1c0663c 100644
--- a/libs/libc/termios/lib_tcsetattr.c
+++ b/libs/libc/termios/lib_tcsetattr.c
@@ -83,10 +83,15 @@
 
 int tcsetattr(int fd, int options, FAR const struct termios *termiosp)
 {
-  if (options == TCSANOW)
+  if (options != TCSANOW)
     {
-      return ioctl(fd, TCSETS, (unsigned long)termiosp);
+      tcdrain(fd);
     }
 
-  return -ENOSYS;
+  if (options == TCSAFLUSH)
+    {
+      tcflush(fd, TCIFLUSH);
+    }
+
+  return ioctl(fd, TCSETS, (unsigned long)termiosp);
 }