diff --git a/transport-native-epoll/src/main/java/io/netty/channel/epoll/AbstractEpollStreamChannel.java b/transport-native-epoll/src/main/java/io/netty/channel/epoll/AbstractEpollStreamChannel.java
index 774cc20acc..3411cc4ae9 100644
--- a/transport-native-epoll/src/main/java/io/netty/channel/epoll/AbstractEpollStreamChannel.java
+++ b/transport-native-epoll/src/main/java/io/netty/channel/epoll/AbstractEpollStreamChannel.java
@@ -282,9 +282,6 @@ public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel {
                 }
             } while (offset < end && localWrittenBytes > 0);
         }
-        if (!done) {
-            setFlag(Native.EPOLLOUT);
-        }
         in.removeBytes(initialExpectedWrittenBytes - expectedWrittenBytes);
         return done;
     }
@@ -328,9 +325,6 @@ public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel {
         }
 
         in.removeBytes(initialExpectedWrittenBytes - expectedWrittenBytes);
-        if (!done) {
-            setFlag(Native.EPOLLOUT);
-        }
         return done;
     }
 
@@ -373,9 +367,6 @@ public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel {
 
         if (done) {
             in.remove();
-        } else {
-            // Returned EAGAIN need to set EPOLLOUT
-            setFlag(Native.EPOLLOUT);
         }
         return done;
     }
@@ -389,12 +380,14 @@ public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel {
             if (msgCount == 0) {
                 // Wrote all messages.
                 clearFlag(Native.EPOLLOUT);
-                break;
+                // Return here so we not set the EPOLLOUT flag.
+                return;
             }
 
             // Do gathering write if the outbounf buffer entries start with more than one ByteBuf.
             if (msgCount > 1 && in.current() instanceof ByteBuf) {
                 if (!doWriteMultiple(in, writeSpinCount)) {
+                    // Break the loop and so set EPOLLOUT flag.
                     break;
                 }
 
@@ -403,10 +396,14 @@ public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel {
                 // listeners.
             } else { // msgCount == 1
                 if (!doWriteSingle(in, writeSpinCount)) {
+                    // Break the loop and so set EPOLLOUT flag.
                     break;
                 }
             }
         }
+        // Underlying descriptor can not accept all data currently, so set the EPOLLOUT flag to be woken up
+        // when it can accept more data.
+        setFlag(Native.EPOLLOUT);
     }
 
     protected boolean doWriteSingle(ChannelOutboundBuffer in, int writeSpinCount) throws Exception {
diff --git a/transport/src/main/java/io/netty/channel/nio/AbstractNioByteChannel.java b/transport/src/main/java/io/netty/channel/nio/AbstractNioByteChannel.java
index 8e58b51163..342d67fba6 100644
--- a/transport/src/main/java/io/netty/channel/nio/AbstractNioByteChannel.java
+++ b/transport/src/main/java/io/netty/channel/nio/AbstractNioByteChannel.java
@@ -178,12 +178,14 @@ public abstract class AbstractNioByteChannel extends AbstractNioChannel {
     protected void doWrite(ChannelOutboundBuffer in) throws Exception {
         int writeSpinCount = -1;
 
+        boolean setOpWrite = false;
         for (;;) {
             Object msg = in.current();
             if (msg == null) {
                 // Wrote all messages.
                 clearOpWrite();
-                break;
+                // Directly return here so incompleteWrite(...) is not called.
+                return;
             }
 
             if (msg instanceof ByteBuf) {
@@ -194,7 +196,6 @@ public abstract class AbstractNioByteChannel extends AbstractNioChannel {
                     continue;
                 }
 
-                boolean setOpWrite = false;
                 boolean done = false;
                 long flushedAmount = 0;
                 if (writeSpinCount == -1) {
@@ -219,13 +220,12 @@ public abstract class AbstractNioByteChannel extends AbstractNioChannel {
                 if (done) {
                     in.remove();
                 } else {
-                    incompleteWrite(setOpWrite);
+                    // Break the loop and so incompleteWrite(...) is called.
                     break;
                 }
             } else if (msg instanceof FileRegion) {
                 FileRegion region = (FileRegion) msg;
                 boolean done = region.transfered() >= region.count();
-                boolean setOpWrite = false;
 
                 if (!done) {
                     long flushedAmount = 0;
@@ -253,7 +253,7 @@ public abstract class AbstractNioByteChannel extends AbstractNioChannel {
                 if (done) {
                     in.remove();
                 } else {
-                    incompleteWrite(setOpWrite);
+                    // Break the loop and so incompleteWrite(...) is called.
                     break;
                 }
             } else {
@@ -261,6 +261,7 @@ public abstract class AbstractNioByteChannel extends AbstractNioChannel {
                 throw new Error();
             }
         }
+        incompleteWrite(setOpWrite);
     }
 
     @Override