DRM accel and debugfs/sysfs

[Jeffrey Hugo]

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.
> 
> [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?

-Jeff

> 
>>
>> [1] 
>> https://cgit.freedesktop.org/drm/drm-misc/commit/?id=99845faae7099cd704ebf67514c1157c26960a26 
>>
>>
>> Regards
>> Stanislaw
>>