diff --git a/libc/stdio/lib_libfread.c b/libc/stdio/lib_libfread.c
index a0aa588169e..d41639d8002 100644
--- a/libc/stdio/lib_libfread.c
+++ b/libc/stdio/lib_libfread.c
@@ -99,7 +99,7 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
 #ifndef CONFIG_STDIO_DISABLE_BUFFERING
       /* Is there an I/O buffer? */
 
-      if (stream->bufstart != NULL)
+      if (stream->fs_bufstart != NULL)
         {
           /* If the buffer is currently being used for write access, then
            * flush all of the buffered write data.  We do not support concurrent
@@ -202,7 +202,8 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
                        * into the buffer.
                        */
 
-                      bytes_read = read(stream->fs_fd, stream->fs_bufread, buffer_available);
+                      bytes_read = read(stream->fs_fd, stream->fs_bufread,
+                                        buffer_available);
                       if (bytes_read < 0)
                         {
                           /* An error occurred on the read.  The error code is
@@ -229,7 +230,10 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
                     }
                 }
             }
-#else
+        }
+      else
+#endif
+        {
           /* Now get any other needed chars from the file. */
 
           while (count > 0)
@@ -259,7 +263,6 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
                 }
             }
         }
-#endif
 
       /* Here after a successful (but perhaps short) read */
 
diff --git a/libc/stdio/lib_libfwrite.c b/libc/stdio/lib_libfwrite.c
index 8cb067933fb..b8c90277e6e 100644
--- a/libc/stdio/lib_libfwrite.c
+++ b/libc/stdio/lib_libfwrite.c
@@ -63,7 +63,6 @@ ssize_t lib_fwrite(FAR const void *ptr, size_t count, FAR FILE *stream)
   FAR const unsigned char *src   = ptr;
   ssize_t ret = ERROR;
   unsigned char *dest;
-  int ret;
 
   /* Make sure that writing to this stream is allowed */
 
@@ -153,7 +152,7 @@ ssize_t lib_fwrite(FAR const void *ptr, size_t count, FAR FILE *stream)
 
   /* Return the number of bytes written */
 
-  ret = src - start;
+  ret = (uintptr_t)src - (uintptr_t)start;
 
 errout_with_semaphore:
   lib_give_semaphore(stream);
diff --git a/libc/stdio/lib_rdflush.c b/libc/stdio/lib_rdflush.c
index 284f59e7d7d..f6269833a13 100644
--- a/libc/stdio/lib_rdflush.c
+++ b/libc/stdio/lib_rdflush.c
@@ -65,7 +65,7 @@ int lib_rdflush(FAR FILE *stream)
 {
   /* Sanity checking */
 
-  if (stream =- NULL)
+  if (stream == NULL)
     {
       set_errno(EBADF);
       return ERROR;
diff --git a/libc/stdio/lib_setvbuf.c b/libc/stdio/lib_setvbuf.c
index 10fbc0e6d0e..7d30a6ea883 100644
--- a/libc/stdio/lib_setvbuf.c
+++ b/libc/stdio/lib_setvbuf.c
@@ -132,7 +132,7 @@ int setvbuf(FAR FILE *stream, FAR char *buffer, int mode, size_t size)
   if ((mode == _IOFBF || mode == _IOLBF) && size == 0 &&
       stream->fs_bufstart == NULL)
     {
-      size = BUFSIZE;
+      size = BUFSIZ;
     }
 
   /* Make sure that we have exclusive access to the stream */
@@ -169,7 +169,7 @@ int setvbuf(FAR FILE *stream, FAR char *buffer, int mode, size_t size)
    * successful.
    */
 
-  flags = stream->fs_flags & ~(__FS_FLAG_LBF | __FS_FLAG_NBF | __FS_FLAG_UBF);
+  flags = stream->fs_flags & ~(__FS_FLAG_LBF | __FS_FLAG_UBF);
 
   /* Allocate a new buffer if one is needed or reuse the existing buffer it
    * is appropriate to do so.
@@ -230,7 +230,6 @@ int setvbuf(FAR FILE *stream, FAR char *buffer, int mode, size_t size)
 
         DEBUGASSERT(size == 0);
         newbuf = NULL;
-        flags |= __FS_FLAG_NBF;
         break;
 
       default:
@@ -276,5 +275,3 @@ errout:
   return ERROR;
 #endif
 }
-
-#endif /* !CONFIG_STDIO_DISABLE_BUFFERING */
diff --git a/libc/stdio/lib_stdoutstream.c b/libc/stdio/lib_stdoutstream.c
index 5884f70bf53..4c77c745fcc 100644
--- a/libc/stdio/lib_stdoutstream.c
+++ b/libc/stdio/lib_stdoutstream.c
@@ -86,19 +86,9 @@ static void stdoutstream_putc(FAR struct lib_outstream_s *this, int ch)
 static int stdoutstream_flush(FAR struct lib_outstream_s *this)
 {
   FAR struct lib_stdoutstream_s *sthis = (FAR struct lib_stdoutstream_s *)this;
-  FAR struct file *stream;
 
   DEBUGASSERT(sthis != NULL && sthis->stream != NULL);
-  stream = sthis->stream;
-
-  if (stream->fs_bufstart != NULL)
-    {
-      return lib_fflush(sthis->stream, true);
-    }
-  else
-    {
-      return OK;
-    }
+  return lib_fflush(sthis->stream, true);
 }
 #endif
 
diff --git a/libc/stdio/lib_stdsostream.c b/libc/stdio/lib_stdsostream.c
index a9957f53c7c..8654b635620 100644
--- a/libc/stdio/lib_stdsostream.c
+++ b/libc/stdio/lib_stdsostream.c
@@ -85,20 +85,10 @@ static void stdsostream_putc(FAR struct lib_sostream_s *this, int ch)
 #ifndef CONFIG_STDIO_DISABLE_BUFFERING
 static int stdsostream_flush(FAR struct lib_sostream_s *this)
 {
-  FAR struct lib_stdsostream_s *sthis = (FAR struct lib_stdoutstream_s *)this;
-  FAR struct file *stream;
+  FAR struct lib_stdsostream_s *sthis = (FAR struct lib_stdsostream_s *)this;
 
   DEBUGASSERT(sthis != NULL && sthis->stream != NULL);
-  stream = sthis->stream;
-
-  if (stream->fs_bufstart != NULL)
-    {
-      return lib_fflush(sthis->stream, true);
-    }
-  else
-    {
-      return OK;  
-    }
+  return lib_fflush(sthis->stream, true);
 }
 #endif
 
@@ -109,10 +99,10 @@ static int stdsostream_flush(FAR struct lib_sostream_s *this)
 static off_t stdsostream_seek(FAR struct lib_sostream_s *this, off_t offset,
                               int whence)
 {
-  FAR struct lib_stdsostream_s *mthis = (FAR struct lib_stdsostream_s *)this;
+  FAR struct lib_stdsostream_s *sthis = (FAR struct lib_stdsostream_s *)this;
 
-  DEBUGASSERT(this);
-  return fseek(mthis->stream, offset, whence);
+  DEBUGASSERT(sthis != NULL && sthis->stream != NULL);
+  return fseek(sthis->stream, offset, whence);
 }
 
 /****************************************************************************