[Intel-gfx] [PATCH] drm/i915: Don't unregister fbdev twice

[Daniel Vetter]

On Wed, Jun 08, 2016 at 01:15:22PM +0200, Lukas Wunner wrote:
> Calling drm_framebuffer_unregister_private() in intel_fbdev_destroy() is
> superfluous because the framebuffer will subsequently be unregistered by
> drm_framebuffer_free() when unreferenced in drm_framebuffer_remove().
> The call is a leftover, when it was introduced by commit 362063619cf6
> ("drm: revamp framebuffer cleanup interfaces"), struct intel_framebuffer
> was still embedded in struct intel_fbdev rather than being a pointer as
> it is today, and drm_framebuffer_remove() wasn't used yet.
> 
> As a bonus, the ID of the framebuffer is no longer 0 in the debug log:
> 
> Before:
>     [   39.680874] [drm:drm_mode_object_unreference] OBJ ID: 0 (3)
>     [   39.680878] [drm:drm_mode_object_unreference] OBJ ID: 0 (2)
>     [   39.680884] [drm:drm_mode_object_unreference] OBJ ID: 0 (1)
> 
> After:
>     [  102.504649] [drm:drm_mode_object_unreference] OBJ ID: 45 (3)
>     [  102.504651] [drm:drm_mode_object_unreference] OBJ ID: 45 (2)
>     [  102.504654] [drm:drm_mode_object_unreference] OBJ ID: 45 (1)
> 
> Signed-off-by: Lukas Wunner <lukas at wunner.de>

Hm yeah. But there's a pile of that particaluar cargo-culting copied all
over the place, would be really good to audit all callers of
unregister_private and fix them all up. A few older drivers still embed
the fbdev fb, but most don't but still use the unregister_private +
cleanup combo.

Nitpick in your subject: s/fbdev/fbdev's fb/

Cheers, Daniel

> ---
>  drivers/gpu/drm/i915/intel_fbdev.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> index ef8e676..4c7ea46 100644
> --- a/drivers/gpu/drm/i915/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> @@ -552,8 +552,6 @@ static void intel_fbdev_destroy(struct drm_device *dev,
>  	drm_fb_helper_fini(&ifbdev->helper);
>  
>  	if (ifbdev->fb) {
> -		drm_framebuffer_unregister_private(&ifbdev->fb->base);
> -
>  		mutex_lock(&dev->struct_mutex);
>  		intel_unpin_fb_obj(&ifbdev->fb->base, BIT(DRM_ROTATE_0));
>  		mutex_unlock(&dev->struct_mutex);
> -- 
> 2.8.1
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch