[PATCH RFC v2 2/9] drm/atomic: Create function to insert CRTC state into a commit

drm_atomic_get_crtc_state() allocates a new CRTC state by duplicating
the current one and inserts it into the atomic commit as a single
operation.

However, a later change will need to insert a CRTC state into a
commit without going through the full allocation and duplication path
in drm_atomic_get_crtc_state().

Extract the state insertion logic into a new static
drm_atomic_commit_set_crtc_state() helper, and convert
drm_atomic_get_crtc_state() to use it.

Signed-off-by: Maxime Ripard <[email protected]>
---
 drivers/gpu/drm/drm_atomic.c | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 7aeeeb2fe472..91219c382d14 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -421,10 +421,27 @@ void __drm_atomic_commit_free(struct kref *ref)
 
 	drm_dev_put(dev);
 }
 EXPORT_SYMBOL(__drm_atomic_commit_free);
 
+static int drm_atomic_commit_set_crtc_state(struct drm_atomic_commit *commit,
+					    struct drm_crtc *crtc,
+					    struct drm_crtc_state *crtc_state)
+{
+	int index = drm_crtc_index(crtc);
+
+	drm_modeset_lock_assert_held(&crtc->mutex);
+
+	commit->crtcs[index].state_to_destroy = crtc_state;
+	commit->crtcs[index].old_state = crtc->state;
+	commit->crtcs[index].new_state = crtc_state;
+	commit->crtcs[index].ptr = crtc;
+	crtc_state->state = commit;
+
+	return 0;
+}
+
 /**
  * drm_atomic_get_crtc_state - get CRTC state
  * @state: global atomic state object
  * @crtc: CRTC to get state object for
  *
@@ -443,11 +460,11 @@ EXPORT_SYMBOL(__drm_atomic_commit_free);
  */
 struct drm_crtc_state *
 drm_atomic_get_crtc_state(struct drm_atomic_commit *state,
 			  struct drm_crtc *crtc)
 {
-	int ret, index = drm_crtc_index(crtc);
+	int ret;
 	struct drm_crtc_state *crtc_state;
 
 	WARN_ON(!state->acquire_ctx);
 	drm_WARN_ON(state->dev, state->checked);
 
@@ -461,15 +478,15 @@ drm_atomic_get_crtc_state(struct drm_atomic_commit *state,
 
 	crtc_state = crtc->funcs->atomic_duplicate_state(crtc);
 	if (!crtc_state)
 		return ERR_PTR(-ENOMEM);
 
-	state->crtcs[index].state_to_destroy = crtc_state;
-	state->crtcs[index].old_state = crtc->state;
-	state->crtcs[index].new_state = crtc_state;
-	state->crtcs[index].ptr = crtc;
-	crtc_state->state = state;
+	ret = drm_atomic_commit_set_crtc_state(state, crtc, crtc_state);
+	if (ret) {
+		crtc->funcs->atomic_destroy_state(crtc, crtc_state);
+		return ERR_PTR(ret);
+	}
 
 	drm_dbg_atomic(state->dev, "Added [CRTC:%d:%s] %p state to %p\n",
 		       crtc->base.id, crtc->name, crtc_state, state);
 
 	return crtc_state;

-- 
2.55.0