Re: [PATCH v1] docs: gpu: rfc: i915_scheduler.rst remove unused directives for namespacing

[Jani Nikula <jani.nikula@intel.com>]

On Mon, 06 Nov 2023, Hunter Chasens <hunter.chasens18@ncf.edu> wrote:
> When running `make htmldocs` the following warnings are given.
>
> ```
> Documentation/gpu/rfc/i915_scheduler.rst:138: WARNING:
> Unknown directive type "c:namespace-push".
>
> .. c:namespace-push:: rfc
> Documentation/gpu/rfc/i915_scheduler.rst:143: WARNING:
> Unknown directive type "c:namespace-pop".
>
> .. c:namespace-pop::
> ```
>
> The kernel test robot also reported it here.
> Link: https://lore.kernel.org/all/202311061623.86pTQrie-lkp@intel.com/
>
> Last year Maryam Tahhan <mtahhan@redhat.com> from Redhat noticed something
> similar. "The missing support of c:namespace-push:: and c:namespace-pop::
> directives by helper scripts for kernel documentation prevents using the
> ``c:function::`` directive with proper namespacing." From the context, it
> sounds like this was brought about from a Sphinx update.
>
> Link: https://lore.kernel.org/all/20221123092321.88558-3-mtahhan@redhat.com/
>
> When compiled the `.. kernel-doc::` literal gives it the same formatting with
> or without the namespace directives present. Due to the above information I
> think it safe to remove these, as they don't seem to do anything but
> throw warnings.

Not so fast!

Looks like this is because namespacing was introduced in Sphinx 3.1
[1]. With earlier Sphinx, you get a warning about the namespace
directives.

However, with newer Sphinx, you get the warning mentioned in commit
f6757dfcfde7 ("drm/doc: fix duplicate declaration warning") if you
remove the namespace directives:

linux/Documentation/gpu/driver-uapi.rst:2279: WARNING: Duplicate C declaration, also defined at rfc/i915_scheduler:3.
Declaration is '.. c:struct:: i915_context_engines_parallel_submit'.

It would be short-sighted to just remove the directives. Sooner or later
we're gong to bump the (IMO extremely conservative) minimum version
requirement.


BR,
Jani.


[1] https://www.sphinx-doc.org/en/master/usage/domains/c.html#namespacing


>
> On Mon, Nov 6, 2023 at 5:31 AM Jani Nikula <jani.nikula@intel.com> wrote:
>>
>> On Mon, 06 Nov 2023, Bagas Sanjaya <bagasdotme@gmail.com> wrote:
>> > On Sat, Nov 04, 2023 at 09:47:08AM -0400, Hunter Chasens wrote:
>> >> diff --git a/Documentation/gpu/rfc/i915_scheduler.rst b/Documentation/gpu/rfc/i915_scheduler.rst
>> >> index c237ebc024cd..23ba7006929b 100644
>> >> --- a/Documentation/gpu/rfc/i915_scheduler.rst
>> >> +++ b/Documentation/gpu/rfc/i915_scheduler.rst
>> >> @@ -135,13 +135,9 @@ Add I915_CONTEXT_ENGINES_EXT_PARALLEL_SUBMIT and
>> >>  drm_i915_context_engines_parallel_submit to the uAPI to implement this
>> >>  extension.
>> >>
>> >> -.. c:namespace-push:: rfc
>> >> -
>> >>  .. kernel-doc:: include/uapi/drm/i915_drm.h
>> >>          :functions: i915_context_engines_parallel_submit
>> >>
>> >> -.. c:namespace-pop::
>> >> -
>>
>> What makes the namespacing unnecessary?
>>
>> $ git grep '.. kernel-doc:: include/uapi/drm/i915_drm.h'
>> Documentation/gpu/driver-uapi.rst:.. kernel-doc:: include/uapi/drm/i915_drm.h
>> Documentation/gpu/rfc/i915_scheduler.rst:.. kernel-doc:: include/uapi/drm/i915_drm.h
>>
>> And you get [1] and [2].
>>
>> >>  Extend execbuf2 IOCTL to support submitting N BBs in a single IOCTL
>> >>  -------------------------------------------------------------------
>> >>  Contexts that have been configured with the 'set_parallel' extension can only
>> >
>> > The warnings go away, thanks!
>>
>> What warnings go away?
>>
>> BR,
>> Jani.
>>
>>
>> [1] https://docs.kernel.org/gpu/driver-uapi.html#c.i915_context_engines_parallel_submit
>> [2] https://docs.kernel.org/gpu/rfc/i915_scheduler.html#c.rfc.i915_context_engines_parallel_submit
>>
>> >
>> > Fixes: f6757dfcfde7 ("drm/doc: fix duplicate declaration warning")
>> > Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
>>
>> --
>> Jani Nikula, Intel

-- 
Jani Nikula, Intel