From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Thu, 22 Mar 2018 17:22:54 +0200
Subject: drm/atomic-helper: WARN if legacy plane fb pointers are bogus when
 committing duplicated state
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Git-commit: 5e78d01fa1a7f1794dfc44a6eb77bfec7a8d590d
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

drm_atomic_helper_commit_duplicated_state() should only be called
resume/reset/load_detect paths where plane->old_fb should always be
NULL and plane->fb should be equal to the new_plane_state->fb.
Assert that is indeed the case.

Cc: martin.peres@free.fr
Cc: chris@chris-wilson.co.uk
Cc: Dave Airlie <airlied@gmail.com> (v1)
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180322152313.6561-5-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/drm_atomic_helper.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3118,8 +3118,13 @@ int drm_atomic_helper_commit_duplicated_
 
 	state->acquire_ctx = ctx;
 
-	for_each_new_plane_in_state(state, plane, new_plane_state, i)
+	for_each_new_plane_in_state(state, plane, new_plane_state, i) {
+		WARN_ON(plane->crtc != new_plane_state->crtc);
+		WARN_ON(plane->fb != new_plane_state->fb);
+		WARN_ON(plane->old_fb);
+
 		state->planes[i].old_state = plane->state;
+	}
 
 	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i)
 		state->crtcs[i].old_state = crtc->state;