From fa365e85f53123e867e8293b7b0c154c6b070f65 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Mon, 20 Jun 2016 06:10:56 -0600
Subject: [PATCH] Update some cmoments

---
 drivers/syslog/vlowsyslog.c   | 4 ++++
 drivers/syslog/vsyslog.c      | 4 ++++
 include/nuttx/syslog/syslog.h | 4 ++++
 libc/syslog/lib_lowsyslog.c   | 7 ++++++-
 libc/syslog/lib_syslog.c      | 7 ++++++-
 5 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/syslog/vlowsyslog.c b/drivers/syslog/vlowsyslog.c
index e3e4051617..7e44474882 100644
--- a/drivers/syslog/vlowsyslog.c
+++ b/drivers/syslog/vlowsyslog.c
@@ -62,6 +62,10 @@
  *   equivalent to vlowsyslog() except that the pre-process priority filtering
  *   has already been performed and, hence, there is no priority argument.
  *
+ *   NOTE:  The va_list parameter is passed by reference.  That is because
+ *   the va_list is a structure in some compilers and passing of structures
+ *   in the NuttX sycalls does not work.
+ *
  ****************************************************************************/
 
 int _lowvsyslog(FAR const IPTR char *fmt, FAR va_list *ap)
diff --git a/drivers/syslog/vsyslog.c b/drivers/syslog/vsyslog.c
index fc9b9a1b9d..8d51c4ad5c 100644
--- a/drivers/syslog/vsyslog.c
+++ b/drivers/syslog/vsyslog.c
@@ -60,6 +60,10 @@
  *   equivalent to vsyslog() except that the pre-process priority filtering
  *   has already been performed and, hence, there is no priority argument.
  *
+ *   NOTE:  The va_list parameter is passed by reference.  That is because
+ *   the va_list is a structure in some compilers and passing of structures
+ *   in the NuttX sycalls does not work.
+ *
  ****************************************************************************/
 
 int _vsyslog(FAR const IPTR char *fmt, FAR va_list *ap)
diff --git a/include/nuttx/syslog/syslog.h b/include/nuttx/syslog/syslog.h
index 18d20c98d2..d38b873217 100644
--- a/include/nuttx/syslog/syslog.h
+++ b/include/nuttx/syslog/syslog.h
@@ -214,6 +214,10 @@ int syslog_flush(void);
  *   equivalent to vsyslog() except that the pre-process priority filtering
  *   has already been performed and, hence, there is no priority argument.
  *
+ *   NOTE:  The va_list parameter is passed by reference.  That is because
+ *   the va_list is a structure in some compilers and passing of structures
+ *   in the NuttX sycalls does not work.
+ *
  ****************************************************************************/
 
 int _vsyslog(FAR const IPTR char *src, FAR va_list *ap);
diff --git a/libc/syslog/lib_lowsyslog.c b/libc/syslog/lib_lowsyslog.c
index d86ab394ff..4f823911c6 100644
--- a/libc/syslog/lib_lowsyslog.c
+++ b/libc/syslog/lib_lowsyslog.c
@@ -78,7 +78,12 @@ int lowvsyslog(int priority, FAR const IPTR char *fmt, va_list ap)
 
   if ((g_syslog_mask & LOG_MASK(priority)) != 0)
     {
-      /* Perform the _lowvsyslog system call */
+      /* Perform the _lowvsyslog system call.
+       *
+       * NOTE:  The va_list parameter is passed by reference.  That is
+       * because the va_list is a structure in some compilers and passing
+       * of structures in the NuttX sycalls does not work.
+       */
 
       ret = _lowvsyslog(fmt, &ap);
     }
diff --git a/libc/syslog/lib_syslog.c b/libc/syslog/lib_syslog.c
index 700b99b48c..ec9ca3b7e5 100644
--- a/libc/syslog/lib_syslog.c
+++ b/libc/syslog/lib_syslog.c
@@ -67,7 +67,12 @@ int vsyslog(int priority, FAR const IPTR char *fmt, va_list ap)
 
   if ((g_syslog_mask & LOG_MASK(priority)) != 0)
     {
-      /* Yes.. lPerform the _vsyslog system cal */
+      /* Yes.. lPerform the _vsyslog system call.
+       *
+       * NOTE:  The va_list parameter is passed by reference.  That is
+       * because the va_list is a structure in some compilers and passing
+       * of structures in the NuttX sycalls does not work.
+       */
 
       ret = _vsyslog(fmt, &ap);
     }