Re: [PATCH 2/2] drm/debugfs: add descriptions to struct parameters

From: Daniel Vetter
Date: Wed Jan 11 2023 - 17:40:53 EST


On Mon, Jan 09, 2023 at 08:28:20AM -0300, Maíra Canal wrote:
> On 1/6/23 17:19, Daniel Vetter wrote:
> > On Thu, Jan 05, 2023 at 04:30:39PM -0300, Maíra Canal wrote:
> > > The structs drm_debugfs_info and drm_debugfs_entry don't have
> > > descriptions for their parameters, which is causing the following warnings:
> > >
> > > include/drm/drm_debugfs.h:93: warning: Function parameter or member
> > > 'name' not described in 'drm_debugfs_info'
> > > include/drm/drm_debugfs.h:93: warning: Function parameter or member
> > > 'show' not described in 'drm_debugfs_info'
> > > include/drm/drm_debugfs.h:93: warning: Function parameter or member
> > > 'driver_features' not described in 'drm_debugfs_info'
> > > include/drm/drm_debugfs.h:93: warning: Function parameter or member
> > > 'data' not described in 'drm_debugfs_info'
> > > include/drm/drm_debugfs.h:105: warning: Function parameter or member
> > > 'dev' not described in 'drm_debugfs_entry'
> > > include/drm/drm_debugfs.h:105: warning: Function parameter or member
> > > 'file' not described in 'drm_debugfs_entry'
> > > include/drm/drm_debugfs.h:105: warning: Function parameter or member
> > > 'list' not described in 'drm_debugfs_entry'
> > >
> > > Therefore, fix the warnings by adding descriptions to all struct
> > > parameters.
> > >
> > > Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> > > Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
> > > ---
> > > include/drm/drm_debugfs.h | 18 ++++++++++++++++++
> > > 1 file changed, 18 insertions(+)
> > >
> > > diff --git a/include/drm/drm_debugfs.h b/include/drm/drm_debugfs.h
> > > index 53b7297260a5..7616f457ce70 100644
> > > --- a/include/drm/drm_debugfs.h
> > > +++ b/include/drm/drm_debugfs.h
> > > @@ -86,9 +86,22 @@ struct drm_info_node {
> > > * core.
> > > */
> > > struct drm_debugfs_info {
> > > + /** @name: File name */
> > > const char *name;
> > > +
> > > + /**
> > > + * @show:
> > > + *
> > > + * Show callback. &seq_file->private will be set to the &struct
> > > + * drm_debugfs_entry corresponding to the instance of this info
> > > + * on a given &struct drm_device.
> >
> > So this is a bit late, but why don't we pass that drm_debugfs_entry as an
> > explicit parameter? Or maybe just the struct drm_device, because that and
> > the void *data is really all there is to pass along. Would give us more
> > type-safety, which really is the main reason for having drm-specific
> > debugfs functions.
>
> It seems like a better idea to pass the drm_debugfs_entry as an explicit
> parameter. I can work on it, but I guess it is a better idea to finish
> the conversion of all drm_debugfs_create_files() to drm_debugfs_add_files()
> and then perform the change in the show() signature.

So drm_debugfs_entry still feels like a bit too high level, do callers
really need that? They get the void * and I guess need the struct
drm_device *

This really starts to matter more when we also roll this out for
connector/crtc, then you can give them directly a pointer to that. And the
drm_debugfs_entry thing becomes an implementation detail entirely.

Or do I miss something?

Also yes we can do that later on, it shouldn't be too annyoing to roll
out.
-Daniel
>
> Best Regards,
> - Maíra Canal
>
> >
> > Either way, on the series: Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> >
> > > + */
> > > int (*show)(struct seq_file*, void*);
> > > +
> > > + /** @driver_features: Required driver features for this entry. */
> > > u32 driver_features;
> > > +
> > > + /** @data: Driver-private data, should not be device-specific. */
> > > void *data;
> > > };
> > > @@ -99,8 +112,13 @@ struct drm_debugfs_info {
> > > * drm_debugfs_info on a &struct drm_device.
> > > */
> > > struct drm_debugfs_entry {
> > > + /** @dev: &struct drm_device for this node. */
> > > struct drm_device *dev;
> > > +
> > > + /** @file: Template for this node. */
> > > struct drm_debugfs_info file;
> > > +
> > > + /** @list: Linked list of all device nodes. */
> > > struct list_head list;
> > > };
> > > --
> > > 2.39.0
> > >
> >

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch