Hi

Am 10.05.22 um 10:37 schrieb Thomas Zimmermann:
...

quoted

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You have to go through all DRM drivers that call drm_fb_helper_fini()
and make sure that they free fb_info. For example armada appears to be
leaking now. [1]

But shouldn't fb_info be freed when unregister_framebuffer() is called
through drm_dev_unregister() ? AFAICT the call chain is the following:

drm_put_dev()
   drm_dev_unregister()
     drm_client_dev_unregister()
       drm_fbdev_client_unregister()
         drm_fb_helper_unregister_fbi()
           unregister_framebuffer()
             do_unregister_framebuffer()
               put_fb_info()
                 drm_fbdev_fb_destroy()
                   framebuffer_release()

which is the reason why I believe that drm_fb_helper_fini() should be
an internal static function and only called from drm_fbdev_fb_destroy().

Drivers shouldn't really explicitly call this helper in my opinion.

One more stupid question: does armada actually use 
drm_fbdev_fb_destroy()? It's supposed to be a callback for struct 
fb_ops. Armada uses it's own instance of fb_ops, which apparently 
doesn't contain fb_destroy. [1]

Best regards
Thomas

[1] 
https://elixir.bootlin.com/linux/v5.17.6/source/drivers/gpu/drm/armada/armada_fbdev.c#L19

Thanks.  That makes sense.

Best regards
Thomas

quoted

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev