[Intel-gfx] [PATCH] drm/i915: unbind fbs from crtcs during driver unload

[Daniel Vetter]

On Wed, Feb 12, 2014 at 12:01:10AM +0200, Imre Deak wrote:
> So far during driver unload we called drm_framebuffer_cleanup() for the
> fbdev fb, which only removes the fb from the drm fb list regardless of
> its reference count, but leaves the fb bound on an active crtc. Since
> the fb's backing storage was freed this could mean we scan some random
> memory content out afterwards. It's not a big issue since the fb is
> allocated from stolen memory and afaik there is no other user for that
> than i915. It's still cleaner to properly unbind the fb and disable the
> crtc, which is what drm_framebuffer_remove() does.
> 
> Note that after
> 
> commit 88891eb1e9eca0ba619518bed31580f91e9cf84d
> Author: Daniel Vetter <daniel.vetter at ffwll.ch>
> Date:   Mon Feb 10 18:00:38 2014 +0100
> 
> we call drm_framebuffer_cleanup() only after dropping the last reference
> on the fb, but that won't happen since we don't unbind the fb. This
> results in a drm core warn about a leaked fb.
> 
> Signed-off-by: Imre Deak <imre.deak at intel.com>

Yeah, makes more sense. Apparently I really don't know my own fb lifetime
rules :( Queued for -next, thanks for the patch.
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_fbdev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> index cf46273..3a53ee3 100644
> --- a/drivers/gpu/drm/i915/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> @@ -265,7 +265,7 @@ static void intel_fbdev_destroy(struct drm_device *dev,
>  	drm_fb_helper_fini(&ifbdev->helper);
>  
>  	drm_framebuffer_unregister_private(&ifbdev->fb->base);
> -	drm_framebuffer_unreference(&ifbdev->fb->base);
> +	drm_framebuffer_remove(&ifbdev->fb->base);
>  }
>  
>  int intel_fbdev_init(struct drm_device *dev)
> -- 
> 1.8.3.2
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch