[tcp|udp]_poll_eventhandler check psock_[tcp|udp]_cansend before report POLLOUT. Change the unbuffered psock_[tcp|udp]_cansend return OK to unify the code logic and remove the unnecessary [tcp|udp]_poll_txnotify call.

net/tcp/tcp_netpoll.c

@@ -120,13 +120,9 @@ static uint16_t tcp_poll_eventhandler(FAR struct net_driver_s *dev,
           eventset |= POLLIN & info->fds->events;
         }
 
-      /* A poll is a sign that we are free to send data.
+      /* A poll is a sign that we are free to send data. */
-       * REVISIT: This is bogus:  If CONFIG_TCP_WRITE_BUFFERS=y then
-       * we never have to wait to send; otherwise, we always have to
-       * wait to send.  Receiving a poll is irrelevant.
-       */
 
-      if ((flags & TCP_POLL) != 0)
+      if ((flags & TCP_POLL) != 0 && psock_tcp_cansend(info->psock) >= 0)
         {
           eventset |= (POLLOUT & info->fds->events);
         }
@@ -244,55 +240,6 @@ static inline void tcp_iob_work(FAR void *arg)
 }
 #endif
 
-/****************************************************************************
- * Name: tcp_poll_txnotify
- *
- * Description:
- *   Notify the appropriate device driver that we are have data ready to
- *   be sent (TCP)
- *
- * Input Parameters:
- *   psock - Socket state structure
- *
- * Returned Value:
- *   None
- *
- ****************************************************************************/
-
-#if !defined(CONFIG_NET_TCP_WRITE_BUFFERS) || !defined(CONFIG_IOB_NOTIFIER)
-static inline void tcp_poll_txnotify(FAR struct socket *psock)
-{
-  FAR struct tcp_conn_s *conn = psock->s_conn;
-
-#ifdef CONFIG_NET_IPv4
-#ifdef CONFIG_NET_IPv6
-  /* If both IPv4 and IPv6 support are enabled, then we will need to select
-   * the device driver using the appropriate IP domain.
-   */
-
-  if (psock->s_domain == PF_INET)
-#endif
-    {
-      /* Notify the device driver that send data is available */
-
-      netdev_ipv4_txnotify(conn->u.ipv4.laddr, conn->u.ipv4.raddr);
-    }
-#endif /* CONFIG_NET_IPv4 */
-
-#ifdef CONFIG_NET_IPv6
-#ifdef CONFIG_NET_IPv4
-  else /* if (psock->s_domain == PF_INET6) */
-#endif /* CONFIG_NET_IPv4 */
-    {
-      /* Notify the device driver that send data is available */
-
-      DEBUGASSERT(psock->s_domain == PF_INET6);
-      netdev_ipv6_txnotify(conn->u.ipv6.laddr, conn->u.ipv6.raddr);
-    }
-#endif /* CONFIG_NET_IPv6 */
-}
-#endif
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -464,8 +411,8 @@ int tcp_pollsetup(FAR struct socket *psock, FAR struct pollfd *fds)
 
 #if defined(CONFIG_NET_TCP_WRITE_BUFFERS) && defined(CONFIG_IOB_NOTIFIER)
   /* If (1) revents == 0, (2) write buffering is enabled, and (3) the
-   * POLLOUT event is needed, then setup to receive a notification an IOB
+   * POLLOUT event is needed, then setup to receive a notification when an
-   * is freed.
+   * IOB is freed.
    */
 
   else if ((fds->events & POLLOUT) != 0)
@@ -474,23 +421,6 @@ int tcp_pollsetup(FAR struct socket *psock, FAR struct pollfd *fds)
 
       info->key = iob_notifier_setup(LPWORK, tcp_iob_work, info);
     }
-
-#else
-  /* If (1) the socket is in a bound state, (2) revents == 0, (3) write
-   * buffering is not enabled (determined by a configuration setting), and
-   * (4) the POLLOUT event is needed then request an immediate Tx poll from
-   * the device associated with the binding.
-   */
-
-  else if (_SS_ISBOUND(psock->s_flags) && (fds->events & POLLOUT) != 0)
-    {
-      /* Note that the notification will fail if the socket is bound to
-       * INADDR_ANY or the IPv6 unspecified address!  In that case the
-       * notification will fail.
-       */
-
-      tcp_poll_txnotify(psock);
-    }
 #endif
 
   net_unlock();

net/tcp/tcp_send_unbuffered.c

@@ -824,7 +824,7 @@ errout:
  *   psock    An instance of the internal socket structure.
  *
  * Returned Value:
- *   -ENOSYS (Function not implemented, always have to wait to send).
+ *   OK (Always can send).
  *
  * Assumptions:
  *   None
@@ -833,7 +833,7 @@ errout:
 
 int psock_tcp_cansend(FAR struct socket *psock)
 {
-  return -ENOSYS;
+  return OK;
 }
 
 #endif /* CONFIG_NET && CONFIG_NET_TCP && !CONFIG_NET_TCP_WRITE_BUFFERS */

net/udp/udp_netpoll.c

@@ -120,13 +120,9 @@ static uint16_t udp_poll_eventhandler(FAR struct net_driver_s *dev,
           eventset |= (POLLIN & info->fds->events);
         }
 
-      /* A poll is a sign that we are free to send data.
+      /* A poll is a sign that we are free to send data. */
-       * REVISIT: This is bogus:  If CONFIG_UDP_WRITE_BUFFERS=y then
-       * we never have to wait to send; otherwise, we always have to
-       * wait to send.  Receiving a poll is irrelevant.
-       */
 
-      if ((flags & UDP_POLL) != 0)
+      if ((flags & UDP_POLL) != 0 && psock_udp_cansend(info->psock) >= 0)
         {
           eventset |= (POLLOUT & info->fds->events);
         }
@@ -217,55 +213,6 @@ static inline void udp_iob_work(FAR void *arg)
 }
 #endif
 
-/****************************************************************************
- * Name: udp_poll_txnotify
- *
- * Description:
- *   Notify the appropriate device driver that we are have data ready to
- *   be sent (UDP)
- *
- * Input Parameters:
- *   psock - Socket state structure
- *
- * Returned Value:
- *   None
- *
- ****************************************************************************/
-
-#if !defined(CONFIG_NET_UDP_WRITE_BUFFERS) || !defined(CONFIG_IOB_NOTIFIER)
-static inline void udp_poll_txnotify(FAR struct socket *psock)
-{
-  FAR struct udp_conn_s *conn = psock->s_conn;
-
-#ifdef CONFIG_NET_IPv4
-#ifdef CONFIG_NET_IPv6
-  /* If both IPv4 and IPv6 support are enabled, then we will need to select
-   * the device driver using the appropriate IP domain.
-   */
-
-  if (psock->s_domain == PF_INET)
-#endif
-    {
-      /* Notify the device driver that send data is available */
-
-      netdev_ipv4_txnotify(conn->u.ipv4.laddr, conn->u.ipv4.raddr);
-    }
-#endif /* CONFIG_NET_IPv4 */
-
-#ifdef CONFIG_NET_IPv6
-#ifdef CONFIG_NET_IPv4
-  else /* if (psock->s_domain == PF_INET6) */
-#endif /* CONFIG_NET_IPv4 */
-    {
-      /* Notify the device driver that send data is available */
-
-      DEBUGASSERT(psock->s_domain == PF_INET6);
-      netdev_ipv6_txnotify(conn->u.ipv6.laddr, conn->u.ipv6.raddr);
-    }
-#endif /* CONFIG_NET_IPv6 */
-}
-#endif
-
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -401,46 +348,6 @@ int udp_pollsetup(FAR struct socket *psock, FAR struct pollfd *fds)
 
       info->key = iob_notifier_setup(LPWORK, udp_iob_work, info);
     }
-
-#else
-  /* If (1) the socket is in a bound state via bind() or via the
-   * UDP_BINDTODEVICE socket options, (2) revents == 0, (3) write buffering
-   * is not enabled (determined by a configuration setting), and (3) the
-   * POLLOUT event is needed then request an immediate Tx poll from the
-   * device associated with the binding.
-   */
-
-  else if ((fds->events & POLLOUT) != 0)
-    {
-      /* Check if the socket has been bound to a local address (might be
-       * INADDR_ANY or the IPv6 unspecified address!  In that case the
-       * notification will fail)
-       */
-
-      if (_SS_ISBOUND(psock->s_flags))
-        {
-          udp_poll_txnotify(psock);
-        }
-
-#ifdef CONFIG_NET_UDP_BINDTODEVICE
-      /* Check if the socket has been bound to a device interface index via
-       * the UDP_BINDTODEVICE socket option.
-       */
-
-      else if (conn->boundto > 0)
-        {
-          /* Yes, find the device associated with the interface index */
-
-          FAR struct net_driver_s *dev = netdev_findbyindex(conn->boundto);
-          if (dev != NULL)
-            {
-              /* And request a poll from the device */
-
-              netdev_txnotify_dev(dev);
-            }
-        }
-#endif
-    }
 #endif
 
   net_unlock();

net/udp/udp_psock_sendto_unbuffered.c

@@ -588,7 +588,7 @@ errout_with_lock:
  *   psock    An instance of the internal socket structure.
  *
  * Returned Value:
- *   -ENOSYS (Function not implemented, always have to wait to send).
+ *   OK (Always can send).
  *
  * Assumptions:
  *   None
@@ -597,7 +597,7 @@ errout_with_lock:
 
 int psock_udp_cansend(FAR struct socket *psock)
 {
-  return -ENOSYS;
+  return OK;
 }
 
 #endif /* CONFIG_NET_UDP */