drm/atomic-helper: Don't call atomic_update_plane when it stays off
It's a silly thing to do and surprises driver writers. Most likely
this did already blow up for exynos.
It's also a silly thing to change plane state when it's off, but fbdev
is silly (it does an unconditional modeset over all planes). And
userspace can be evil. So I think we need this.
With this check in the helpers we can remove the one in i915 code for
the same conditions (becuase ->crtc iff ->fb).
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: dri-devel@lists.freedesktop.org
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index a2fb0d4..d536817 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1138,7 +1138,8 @@
if (drm_atomic_plane_disabling(plane, old_plane_state) &&
funcs->atomic_disable)
funcs->atomic_disable(plane, old_plane_state);
- else
+ else if (plane->state->crtc ||
+ drm_atomic_plane_disabling(plane, old_plane_state))
funcs->atomic_update(plane, old_plane_state);
}