[PATCH 3/4] drm/rockchip: vop2: Don't crash for invalid duplicate_state

[Jonas Karlman <jonas@kwiboo.se>]

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: 604be85547ce ("drm/rockchip: Add VOP2 driver")
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
---
 drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
index ca73b8ccc29f..f725487d02ef 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
@@ -2099,11 +2099,13 @@ static void vop2_crtc_reset(struct drm_crtc *crtc)
 
 static struct drm_crtc_state *vop2_crtc_duplicate_state(struct drm_crtc *crtc)
 {
-	struct rockchip_crtc_state *vcstate, *old_vcstate;
+	struct rockchip_crtc_state *vcstate;
 
-	old_vcstate = to_rockchip_crtc_state(crtc->state);
+	if (WARN_ON(!crtc->state))
+		return NULL;
 
-	vcstate = kmemdup(old_vcstate, sizeof(*old_vcstate), GFP_KERNEL);
+	vcstate = kmemdup(to_rockchip_crtc_state(crtc->state),
+			  sizeof(*vcstate), GFP_KERNEL);
 	if (!vcstate)
 		return NULL;
 
-- 
2.41.0