[urgent] drm/fb-helper: Fix the dummy remove_conflicting_framebuffers

[Daniel Vetter]

On Mon, Aug 22, 2016 at 09:44:52PM +0100, Chris Wilson wrote:
> We always need to remove conflicting framebuffers if any other fb driver
> is enabled, and not just if we are setting up an fbdev ourselves.
> 
> Unfortunately remove_conflicting_framebuffers() was incorrectly stubbed
> out if !fbdev rather than !fb leading to major memory corruption (and
> corrupt filesystems) upon boot.
> 
> Fixes: 44adece57e26 ("drm/fb-helper: Add a dummy remove_conflicting_framebuffers")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Tobias Jakobi <tjakobi at math.uni-bielefeld.de>
> Cc: Noralf Trønnes <noralf at tronnes.org>
> Cc: tomi.valkeinen at ti.com
> Cc: dh.herrmann at gmail.com
> Cc: Alex Deucher <alexander.deucher at amd.com>

It's only in -misc, so not super urgent. Applied, thanks.
-Daniel

> ---
>  include/drm/drm_fb_helper.h | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> index 97889a90ff23..f811d755c254 100644
> --- a/include/drm/drm_fb_helper.h
> +++ b/include/drm/drm_fb_helper.h
> @@ -282,12 +282,6 @@ drm_pick_cmdline_mode(struct drm_fb_helper_connector *fb_helper_conn,
>  int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector);
>  int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
>  				       struct drm_connector *connector);
> -static inline int
> -drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a,
> -					      const char *name, bool primary)
> -{
> -	return remove_conflicting_framebuffers(a, name, primary);
> -}
>  #else
>  static inline int drm_fb_helper_modinit(void)
>  {
> @@ -482,11 +476,17 @@ drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
>  	return 0;
>  }
>  
> +#endif
> +
>  static inline int
>  drm_fb_helper_remove_conflicting_framebuffers(struct apertures_struct *a,
>  					      const char *name, bool primary)
>  {
> +#if IS_ENABLED(CONFIG_FB)
> +	return remove_conflicting_framebuffers(a, name, primary);
> +#else
>  	return 0;
> -}
>  #endif
> +}
> +
>  #endif
> -- 
> 2.9.3
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch