[PATCH RFC 03/25] drm/atomic-helper: Set mode_changed on vrr_enabled change

[Nicolas Frattaroli <nicolas.frattaroli@collabora.com>]

A change in whether VRR is enabled or not on a CRTC will be of interest
to any VRR implementation, as they may need to recalculate certain
internal state in response. So far, this was handled ad-hoc in the
drivers that implement VRR.

Handle this in the common DRM atomic core by setting the mode_changed
flag when this occurs. The rationale for using mode_changed is that VRR
is deeply intertwined with the current mode with regards to its timing.
Consequently, any component that cares about a mode change is likely
also going to care about VRR being enabled/disabled.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
---
 drivers/gpu/drm/drm_atomic_helper.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 9d006f98413a..0664d5779282 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -694,6 +694,12 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
 			new_crtc_state->active_changed = true;
 		}
 
+		if (old_crtc_state->vrr_enabled != new_crtc_state->vrr_enabled) {
+			drm_dbg_atomic(dev, "[CRTC:%d:%s] VRR changed\n",
+				       crtc->base.id, crtc->name);
+			new_crtc_state->mode_changed = true;
+		}
+
 		if (new_crtc_state->enable != has_connectors) {
 			drm_dbg_atomic(dev, "[CRTC:%d:%s] enabled/connectors mismatch (%d/%d)\n",
 				       crtc->base.id, crtc->name,

-- 
2.55.0