Commit 731cce48 authored Apr 23, 2014 by Daniel Vetter

drm: Handle ->disable_plane failures correctly



The ->disable_plane hook always had a return value, but only since the
introduction of primary planes was there any implementation that
actually failed.

So handle such failures correctly.

Note that drm_plane_force_disable is special: In the modeset cleanup
case we first disable all crtc, so primary planes should all be freed
already. And in the fb helper we only reset non-primary planes. Still
better be paranoid and add an early return.

I don't see how this could happen, but it might fix the fb refcount
underrun Thierry is seeing. Matt Roper spotted this issue.

Cc: Thierry Reding <treding@nvidia.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

parent 0fe27f06

drivers/gpu/drm/drm_crtc.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -1152,8 +1152,10 @@ void drm_plane_force_disable(struct drm_plane *plane)
		return;

		ret = plane->funcs->disable_plane(plane);
		if (ret)
		if (ret) {
		DRM_ERROR("failed to disable plane with busy fb\n");
		return;
		}
		/* disconnect the plane from the fb and crtc: */
		__drm_framebuffer_unreference(old_fb);
		plane->fb = NULL;
		@@ -2117,9 +2119,13 @@ int drm_mode_setplane(struct drm_device dev, void data,
		if (!plane_req->fb_id) {
		drm_modeset_lock_all(dev);
		old_fb = plane->fb;
		plane->funcs->disable_plane(plane);
		ret = plane->funcs->disable_plane(plane);
		if (!ret) {
		plane->crtc = NULL;
		plane->fb = NULL;
		} else {
		old_fb = NULL;
		}
		drm_modeset_unlock_all(dev);
		goto out;
		}