DRM accel and debugfs/sysfs

[Oded Gabbay]

On Wed, Feb 8, 2023 at 8:07 PM Daniel Vetter <daniel at ffwll.ch> wrote:
>
> On Tue, Feb 07, 2023 at 01:17:47PM -0300, Maíra Canal wrote:
> > On 2/7/23 12:43, Jeffrey Hugo wrote:
> > > On 2/7/2023 4:31 AM, Maíra Canal wrote:
> > > > Hi Stanislaw,
> > > >
> > > > On 2/1/23 12:20, Stanislaw Gruszka wrote:
> > > > > Hi
> > > > >
> > > > > I was about to send debugfs support for ivpu and noticed that there
> > > > > are current changes that deprecate drm_devel->debugfs_init callback.
> > > > >
> > > > > Further I looked at this commit [1], that stated we should not
> > > > > use drm_minor for debugfs and sysfs. What is quite contrary to
> > > > > what drm accel framework did in the first place.
> > > > >
> > > > > So my question is how we should use debugfs/sysfs in accel?
> > > > > Use it with old fashioned minor-centric way or change
> > > > > the framework somehow ?
> > > >
> > > > As we are trying to replace drm_debugfs_create_files() [1], it would
> > > > be nice to see the accel debugfs support use the new debugfs API. This
> > > > would mean using the debugfs_list from the drm_device, deprecating
> > > > the debugfs_init callback, and adding the a similar code snippet to
> > > > accel_debugfs_init:
> > > >
> > > > list_for_each_entry_safe(entry, tmp, &dev->debugfs_list, list) {
> > > >      debugfs_create_file(entry->file.name, 0444,
> > > >                  minor->debugfs_root, entry, &drm_debugfs_entry_fops);
> > > >      list_del(&entry->list);
> > > >
> > > > Maybe Daniel has some more thoughts on this matter, but I guess it
> > > > would be better to drop the use of the old-fashioned minor-centric
> > > > implementation in accel.
>
> It was a simple case of two things landing in parallel and not being
> synchronized. Would be good if accel could be adapted to use the new
> debugfs infra, now that both accel and the new debugfs stuff have landed.
> -Daniel
Yes, definitely.
Does anyone volunteer to send a patch to align ?
If not, we will do it internally and send a patch.

Oded
>
> > > >
> > > > [1] https://cgit.freedesktop.org/drm/drm-misc/tree/Documentation/gpu/todo.rst#n511
> > > >
> > > > Best Regards,
> > > > - Maíra Canal
> > >
> > > Thank you for the details Maira.  It helps to explain what the todo is suggesting.  Is there an example of a driver/drm_device that uses debugfs_list which you can easily point to?
> >
> > The implementation of this device-centered infrastructure is linked in [1]
> > and an example of the conversion of debugfs APIs is linked in [2], and other
> > drivers such as v3d, vkms, vc4 and gud use this new API as well.
> >
> > [1] https://cgit.freedesktop.org/drm/drm-misc/commit/?id=1c9cacbea880513a896aee65a5c58007bcb55653
> > [2] https://cgit.freedesktop.org/drm/drm-misc/commit/?id=2e3ab8a6994f265bbd4dbd00448b84548f18464c
> >
> > Best Regards,
> > - Maíra Canal
> >
> > >
> > > -Jeff
> > >
> > > >
> > > > >
> > > > > [1] https://cgit.freedesktop.org/drm/drm-misc/commit/?id=99845faae7099cd704ebf67514c1157c26960a26
> > > > >
> > > > > Regards
> > > > > Stanislaw
> > > > >
> > >
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch