net/tcp/tcp_send.c: Commit a52ceac13e broke IPv4 sending. In cp_send.c:tcp_ipv4_sendcomplete(), ‘ipv4->vhl’ now needs to be configured before call to tcp_ipv4_chksum(). Noted by Jussi Kivilinna in comit comments.

fs/procfs/Kconfig

@@ -126,5 +126,5 @@ config FS_PROCFS_EXCLUDE_SMARTFS
 	depends on FS_SMARTFS
 	default n
 
-endmenu #
+endmenu # Exclude individual procfs entries
 endif # FS_PROCFS

net/tcp/tcp_send.c

@@ -138,6 +138,7 @@ static inline void tcp_ipv4_sendcomplete(FAR struct net_driver_s *dev,
 
   ipv4->proto       = IP_PROTO_TCP;
   ipv4->ttl         = IP_TTL;
+  ipv4->vhl         = 0x45;
 
   /* At this point the TCP header holds the size of the payload, the
    * TCP header, and the IP header.