Re: [Intel-gfx] [PATCH 05/24] drm/i915/vma: fix struct i915_vma_bindinfo kernel-doc

[Rodrigo Vivi <rodrigo.vivi@kernel.org>]

On Thu, May 04, 2023 at 12:43:05PM +0300, Jani Nikula wrote:
> On Wed, 03 May 2023, Rodrigo Vivi <rodrigo.vivi@kernel.org> wrote:
> > On Tue, May 02, 2023 at 06:37:22PM +0300, Jani Nikula wrote:
> >> You can't document both a sub-struct type and a struct member at the
> >> same time. Separate them.
> >
> > another way would be to kill the 'i915_vma_bindinfo' name entirely and
> > document only as '@bi:' and then move the individual documentations near
> > their definitions.
> 
> I don't think that will work, because AFAIK kernel-doc does not descend
> into struct members recursively.

It does:

'In-line member documentation comments' definition of:
Documentation/doc-guide/kernel-doc.rst

> 
> You can either declare and document the sub-structs as separate types
> (the patch at hand), or you can document sub-struct members directly
> from the embedding struct as shown below. I don't think the latter is
> very nice.

what I had in mind was something more like:

        /**
-        * struct i915_vma_bindinfo - Information needed for async bind
-        * only but that can be dropped after the bind has taken place.
-        * Consider making this a separate argument to the bind_vma
-        * op, coalescing with other arguments like vm, stash, cache_level
-        * and flags
-        * @pages: The pages sg-table.
-        * @page_sizes: Page sizes of the pages.
-        * @pages_rsgt: Refcounted sg-table when delayed object destruction
-        * is supported. May be NULL.
-        * @readonly: Whether the vma should be bound read-only.
-        * @lmem: Whether the vma points to lmem.
+        * @bi: Information needed for async bind only but that can be dropped
+        *      after the bind has taken place.
+        *      Consider making this a separate argument to the bind_vma
+        *      op, coalescing with other arguments like vm, stash, cache_level
+        *      and flags
         */
-       struct i915_vma_bindinfo {
+       struct {
+               /** @pages: The pages sg-table. */
                struct sg_table *pages;
+               /** @page_sizes: Page sizes of the pages. */
                struct i915_page_sizes page_sizes;
+               /**
+                * @pages_rsgt: Refcounted sg-table when delayed object
+                *              destruction is supported. May be NULL.
+                */
                struct i915_refct_sgt *pages_rsgt;
+               /** @readonly: Whether the vma should be bound read-only. */
                bool readonly:1;
+               /** @lmem: Whether the vma points to lmem. */
                bool lmem:1;
        } bi;


But let's not block the progress of the much needed fixes. It's your call:

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> 
> BR,
> Jani.
> 
> 
> index 2053c037dbfb..ee767cc4de43 100644
> --- a/drivers/gpu/drm/i915/i915_vma_resource.h
> +++ b/drivers/gpu/drm/i915/i915_vma_resource.h
> @@ -48,6 +48,12 @@ struct i915_page_sizes {
>   * @rb: Rb node for the vm's pending unbind interval tree.
>   * @__subtree_last: Interval tree private member.
>   * @wakeref: wakeref.
> + * @bi.pages: The pages sg-table.
> + * @bi.page_sizes: Page sizes of the pages.
> + * @bi.pages_rsgt: Refcounted sg-table when delayed object destruction
> + * is supported. May be NULL.
> + * @bi.readonly: Whether the vma should be bound read-only.
> + * @bi.lmem: Whether the vma points to lmem.
>   * @vm: non-refcounted pointer to the vm. This is for internal use only and
>   * this member is cleared after vm_resource unbind.
>   * @mr: The memory region of the object pointed to by the vma.
> @@ -89,17 +95,11 @@ struct i915_vma_resource {
>         intel_wakeref_t wakeref;
>  
>         /**
> -        * struct i915_vma_bindinfo - Information needed for async bind
> -        * only but that can be dropped after the bind has taken place.
> -        * Consider making this a separate argument to the bind_vma
> -        * op, coalescing with other arguments like vm, stash, cache_level
> -        * and flags
> -        * @pages: The pages sg-table.
> -        * @page_sizes: Page sizes of the pages.
> -        * @pages_rsgt: Refcounted sg-table when delayed object destruction
> -        * is supported. May be NULL.
> -        * @readonly: Whether the vma should be bound read-only.
> -        * @lmem: Whether the vma points to lmem.
> +        * @bi: Information needed for async bind only but that can be dropped
> +        * after the bind has taken place.
> +        *
> +        * Consider making this a separate argument to the bind_vma op,
> +        * coalescing with other arguments like vm, stash, cache_level and flags
>          */
>         struct i915_vma_bindinfo {
>                 struct sg_table *pages;
> 
> 
> >
> >> 
> >> drivers/gpu/drm/i915/i915_vma_resource.h:91: warning: Incorrect use of kernel-doc format:          * struct i915_vma_bindinfo - Information needed for async bind
> >> drivers/gpu/drm/i915/i915_vma_resource.h:129: warning: Function parameter or member 'bi' not described in 'i915_vma_resource'
> >> 
> >> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/i915_vma_resource.h | 45 ++++++++++++++----------
> >>  1 file changed, 27 insertions(+), 18 deletions(-)
> >> 
> >> diff --git a/drivers/gpu/drm/i915/i915_vma_resource.h b/drivers/gpu/drm/i915/i915_vma_resource.h
> >> index 2053c037dbfb..ca2b0f7f59bc 100644
> >> --- a/drivers/gpu/drm/i915/i915_vma_resource.h
> >> +++ b/drivers/gpu/drm/i915/i915_vma_resource.h
> >> @@ -33,6 +33,27 @@ struct i915_page_sizes {
> >>  	unsigned int sg;
> >>  };
> >>  
> >> +/**
> >> + * struct i915_vma_bindinfo - Information needed for async bind
> >> + * only but that can be dropped after the bind has taken place.
> >> + * Consider making this a separate argument to the bind_vma
> >> + * op, coalescing with other arguments like vm, stash, cache_level
> >> + * and flags
> >> + * @pages: The pages sg-table.
> >> + * @page_sizes: Page sizes of the pages.
> >> + * @pages_rsgt: Refcounted sg-table when delayed object destruction
> >> + * is supported. May be NULL.
> >> + * @readonly: Whether the vma should be bound read-only.
> >> + * @lmem: Whether the vma points to lmem.
> >> + */
> >> +struct i915_vma_bindinfo {
> >> +	struct sg_table *pages;
> >> +	struct i915_page_sizes page_sizes;
> >> +	struct i915_refct_sgt *pages_rsgt;
> >> +	bool readonly:1;
> >> +	bool lmem:1;
> >
> > btw, I believe we should move all the individual docs near to its
> > declarations. easier to forget updating the documentation when updating
> > fields here.
> >
> >> +};
> >> +
> >>  /**
> >>   * struct i915_vma_resource - Snapshotted unbind information.
> >>   * @unbind_fence: Fence to mark unbinding complete. Note that this fence
> >> @@ -89,25 +110,13 @@ struct i915_vma_resource {
> >>  	intel_wakeref_t wakeref;
> >>  
> >>  	/**
> >> -	 * struct i915_vma_bindinfo - Information needed for async bind
> >> -	 * only but that can be dropped after the bind has taken place.
> >> -	 * Consider making this a separate argument to the bind_vma
> >> -	 * op, coalescing with other arguments like vm, stash, cache_level
> >> -	 * and flags
> >> -	 * @pages: The pages sg-table.
> >> -	 * @page_sizes: Page sizes of the pages.
> >> -	 * @pages_rsgt: Refcounted sg-table when delayed object destruction
> >> -	 * is supported. May be NULL.
> >> -	 * @readonly: Whether the vma should be bound read-only.
> >> -	 * @lmem: Whether the vma points to lmem.
> >> +	 * @bi: Information needed for async bind only but that can be dropped
> >> +	 * after the bind has taken place.
> >> +	 *
> >> +	 * Consider making this a separate argument to the bind_vma op,
> >> +	 * coalescing with other arguments like vm, stash, cache_level and flags
> >>  	 */
> >> -	struct i915_vma_bindinfo {
> >> -		struct sg_table *pages;
> >> -		struct i915_page_sizes page_sizes;
> >> -		struct i915_refct_sgt *pages_rsgt;
> >> -		bool readonly:1;
> >> -		bool lmem:1;
> >> -	} bi;
> >> +	struct i915_vma_bindinfo bi;
> >>  
> >>  #if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
> >>  	struct intel_memory_region *mr;
> >> -- 
> >> 2.39.2
> >> 
> 
> -- 
> Jani Nikula, Intel Open Source Graphics Center