On Fri, Feb 17, 2023 at 12:49:41PM +0200, Jani Nikula wrote: > On Fri, 17 Feb 2023, Stanislaw Gruszka <stanislaw.gruszka@xxxxxxxxxxxxxxx> wrote: > > On Thu, Feb 16, 2023 at 07:06:46PM +0200, Jani Nikula wrote: > >> > > >> > But should not this the driver responsibility, call drm_debugfs_add_file() > >> > whenever you are ready to handle operations on added file ? > >> > >> In theory, yes, but in practice it's pretty hard for a non-trivial > >> driver to maintain that all the conditions are met. > > > > Hmmm... > > > >> In i915 we call debugfs register all over the place only after we've > >> called drm_dev_register(), because it's the only sane way. But it means > >> we need the init and register separated everywhere, instead of init > >> adding files to a list to be registered later. > > > > Isn't this done this way in i915 only because it was not possible > > (and still isn't) to call drm_debugfs_create_file() before registration ? > > > > I think it's should be ok by i915 subsystem to create it's debugfs > > files and allow to access to them just after that subsystem init. > > > > Or there are some complex dependencies between i915 subsystems, > > that reading registers from one subsystem will corrupt some > > other subsystem that did non finish initialization yet? > > That's the point. It's really hard to figure it all out. Why bother? I see. Just hope we could get something simpler to limit debugfs access before registration: unix hidden file, permissions or other way. Because current drm_debufs_add_file() implementation looks really over convoluted to me. Regards Stanislaw
