[PATCH v2 2/6] drm/nouveau/kms/nv50-: Add nv50_outp_get_old_crtc()

[Lyude Paul <lyude@redhat.com>]

Does what it says on the label, unused for now.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: f575f2bdb6c3 ("drm/nouveau/kms/nv50-: Remove (nv_encoder->crtc) checks in ->disable callbacks")
Cc: <stable@vger.kernel.org> # v5.12+
---
 drivers/gpu/drm/nouveau/dispnv50/disp.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
index a885394f7cb92..152361f7feb42 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -459,6 +459,22 @@ nv50_outp_get_old_connector(struct drm_atomic_commit *state, struct nouveau_enco
 	return NULL;
 }
 
+static struct nouveau_crtc * __maybe_unused
+nv50_outp_get_old_crtc(const struct drm_atomic_commit *state, const struct nouveau_encoder *outp)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	const u32 mask = drm_encoder_mask(&outp->base.base);
+	int i;
+
+	for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
+		if (crtc_state->encoder_mask & mask)
+			return nouveau_crtc(crtc);
+	}
+
+	return NULL;
+}
+
 static struct nouveau_crtc *
 nv50_outp_get_new_crtc(const struct drm_atomic_commit *state, const struct nouveau_encoder *outp)
 {
-- 
2.55.0