having trouble generating some Doc. warnings

kernel test robot reports kernel-doc problems like:

quoted

drivers/pinctrl/aspeed/pinmux-aspeed.c:61: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst

    * Query the enabled or disabled state for a mux function's signal on a pin

where the source code is:

/**
 * Query the enabled or disabled state for a mux function's signal on a pin
 *
 * @ctx: The driver context for the pinctrl IP
 * @expr: An expression controlling the signal for a mux function on a pin
 * @enabled: True to query the enabled state, false to query disabled state


However, I cannot get kernel-doc to report such warnings even though I use
$ make W=1 htmldocs

What else do I need to do? What am I doing wrong?


Update: I can get this warning if I check only one file.
How can I do this for the entire kernel source tree?


thanks.
-- 
~Randy