[PATCH 3/6] amd/display: fail on cursor plane without an underlying plane

[Simon Ser]

Make sure there's an underlying pipe that can be used for the
cursor.

Signed-off-by: Simon Ser <contact at emersion.fr>
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: Harry Wentland <hwentlan at amd.com>
Cc: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index acbe1537e7cf..a5d6010405bf 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -9226,9 +9226,14 @@ static int dm_check_crtc_cursor(struct drm_atomic_state *state,
 	}
 
 	new_cursor_state = drm_atomic_get_new_plane_state(state, crtc->cursor);
-	if (!new_cursor_state || !new_underlying_state || !new_cursor_state->fb)
+	if (!new_cursor_state || !new_cursor_state->fb)
 		return 0;
 
+	if (!new_underlying_state || !new_underlying_state->fb) {
+		drm_dbg_atomic(crtc->dev, "Cursor plane can't be enabled without underlying plane\n");
+		return -EINVAL;
+	}
+
 	cursor_scale_w = new_cursor_state->crtc_w * 1000 /
 			 (new_cursor_state->src_w >> 16);
 	cursor_scale_h = new_cursor_state->crtc_h * 1000 /
-- 
2.30.1