[PATCH 5.15 312/779] drm/rockchip: vop: Dont crash for invalid duplicate_state()

[Greg Kroah-Hartman]

From: Brian Norris <briannorris@xxxxxxxxxxxx>

[ Upstream commit 1449110b0dade8b638d2c17ab7c5b0ff696bfccb ]

It's possible for users to try to duplicate the CRTC state even when the
state doesn't exist. drm_atomic_helper_crtc_duplicate_state() (and other
users of __drm_atomic_helper_crtc_duplicate_state()) already guard this
with a WARN_ON() instead of crashing, so let's do that here too.

Fixes: 4e257d9eee23 ("drm/rockchip: get rid of rockchip_drm_crtc_mode_config")
Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220617172623.1.I62db228170b1559ada60b8d3e1637e1688424926@changeid
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index 8b4287d40379..d5b74ea06a45 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1550,6 +1550,9 @@ static struct drm_crtc_state *vop_crtc_duplicate_state(struct drm_crtc *crtc)
 {
 	struct rockchip_crtc_state *rockchip_state;
 
+	if (WARN_ON(!crtc->state))
+		return NULL;
+
 	rockchip_state = kzalloc(sizeof(*rockchip_state), GFP_KERNEL);
 	if (!rockchip_state)
 		return NULL;
-- 
2.35.1