[PATCH] drm: Simplify fb refcounting rules around ->update_plane

[Thierry Reding]

On Tue, Apr 22, 2014 at 11:07:13AM +0200, Daniel Vetter wrote:
[...]
> diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c
> index e768d35ff22e..8db129c44fea 100644
> --- a/drivers/gpu/drm/drm_plane_helper.c
> +++ b/drivers/gpu/drm/drm_plane_helper.c
> @@ -175,22 +175,7 @@ int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
>  	set.connectors = connector_list;
>  	set.num_connectors = num_connectors;
>  
> -	/*
> -	 * set_config() adjusts crtc->primary->fb; however the DRM setplane
> -	 * code that called us expects to handle the framebuffer update and
> -	 * reference counting; save and restore the current fb before
> -	 * calling it.
> -	 *
> -	 * N.B., we call set_config() directly here rather than using
> -	 * drm_mode_set_config_internal.  We're reprogramming the same
> -	 * connectors that were already in use, so we shouldn't need the extra
> -	 * cross-CRTC fb refcounting to accomodate stealing connectors.
> -	 * drm_mode_setplane() already handles the basic refcounting for the
> -	 * framebuffers involved in this operation.
> -	 */
> -	tmpfb = plane->fb;
>  	ret = crtc->funcs->set_config(&set);
> -	plane->fb = tmpfb;

This makes tmpfb unused. Other than that this looks sane to me and it
doesn't make things worse from what I can tell:

Tested-by: Thierry Reding <treding at nvidia.com>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 836 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20140422/bbdd43b3/attachment.sig>