From: Daniel Vetter Date: Wed, 23 Apr 2014 08:24:11 +0000 (+0200) Subject: drm: Handle ->disable_plane failures correctly X-Git-Tag: next-20140519~62^2~1^2~9 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=731cce487ab0485c6607e44a0759d92bef1c144e;p=karo-tx-linux.git 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 Cc: Ville Syrjälä Cc: Matt Roper Reviewed-by: Matt Roper Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index f6633cb927bc..461d19bd14ee 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -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); - plane->crtc = NULL; - plane->fb = NULL; + 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; }