drm/msm: Convert to using __drm_atomic_helper_crtc_reset() for reset.

Convert msm to using __drm_atomic_helper_crtc_reset(), instead of
writing its own version. Instead of open coding
destroy_state(), call it directly for freeing the old state.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
[mlankhorst: Remove double assignment of mdp5_cstate in reset (seanpaul)]
Reviewed-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20190301125627.7285-11-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c

@@ -753,14 +753,12 @@ void dpu_crtc_commit_kickoff(struct drm_crtc *crtc, bool async)
 
 static void dpu_crtc_reset(struct drm_crtc *crtc)
 {
-	struct dpu_crtc_state *cstate;
+	struct dpu_crtc_state *cstate = kzalloc(sizeof(*cstate), GFP_KERNEL);
 
 	if (crtc->state)
 		dpu_crtc_destroy_state(crtc, crtc->state);
 
-	crtc->state = kzalloc(sizeof(*cstate), GFP_KERNEL);
-	if (crtc->state)
-		crtc->state->crtc = crtc;
+	__drm_atomic_helper_crtc_reset(crtc, &cstate->base);
 }
 
 /**

drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c

@@ -1002,23 +1002,6 @@ mdp5_crtc_atomic_print_state(struct drm_printer *p,
 	drm_printf(p, "\tcmd_mode=%d\n", mdp5_cstate->cmd_mode);
 }
 
-static void mdp5_crtc_reset(struct drm_crtc *crtc)
-{
-	struct mdp5_crtc_state *mdp5_cstate;
-
-	if (crtc->state) {
-		__drm_atomic_helper_crtc_destroy_state(crtc->state);
-		kfree(to_mdp5_crtc_state(crtc->state));
-	}
-
-	mdp5_cstate = kzalloc(sizeof(*mdp5_cstate), GFP_KERNEL);
-
-	if (mdp5_cstate) {
-		mdp5_cstate->base.crtc = crtc;
-		crtc->state = &mdp5_cstate->base;
-	}
-}
-
 static struct drm_crtc_state *
 mdp5_crtc_duplicate_state(struct drm_crtc *crtc)
 {
@@ -1046,6 +1029,17 @@ static void mdp5_crtc_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state
 	kfree(mdp5_cstate);
 }
 
+static void mdp5_crtc_reset(struct drm_crtc *crtc)
+{
+	struct mdp5_crtc_state *mdp5_cstate =
+		kzalloc(sizeof(*mdp5_cstate), GFP_KERNEL);
+
+	if (crtc->state)
+		mdp5_crtc_destroy_state(crtc, crtc->state);
+
+	__drm_atomic_helper_crtc_reset(crtc, &mdp5_cstate->base);
+}
+
 static const struct drm_crtc_funcs mdp5_crtc_funcs = {
 	.set_config = drm_atomic_helper_set_config,
 	.destroy = mdp5_crtc_destroy,