[PATCH 01/18] drm/atomic: add connectors_changed to separate it from mode_changed

[Maarten Lankhorst]

This can be a separate case from mode_changed, when connectors stay the
same but only the mode is different. Drivers may choose to implement specific
optimizations to prevent a full modeset for this case.

Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/drm_atomic_helper.c  | 25 +++++++++++++++++++------
 drivers/gpu/drm/i915/intel_display.c |  2 +-
 include/drm/drm_atomic.h             |  3 ++-
 include/drm/drm_crtc.h               |  8 +++++---
 4 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index d4a7b9fd43c7..41a3d86816b8 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -124,7 +124,7 @@ steal_encoder(struct drm_atomic_state *state,
 	if (IS_ERR(crtc_state))
 		return PTR_ERR(crtc_state);
 
-	crtc_state->mode_changed = true;
+	crtc_state->connectors_changed = true;
 
 	list_for_each_entry(connector, &config->connector_list, head) {
 		if (connector->state->best_encoder != encoder)
@@ -174,14 +174,14 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx)
 			idx = drm_crtc_index(connector->state->crtc);
 
 			crtc_state = state->crtc_states[idx];
-			crtc_state->mode_changed = true;
+			crtc_state->connectors_changed = true;
 		}
 
 		if (connector_state->crtc) {
 			idx = drm_crtc_index(connector_state->crtc);
 
 			crtc_state = state->crtc_states[idx];
-			crtc_state->mode_changed = true;
+			crtc_state->connectors_changed = true;
 		}
 	}
 
@@ -233,7 +233,7 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx)
 	idx = drm_crtc_index(connector_state->crtc);
 
 	crtc_state = state->crtc_states[idx];
-	crtc_state->mode_changed = true;
+	crtc_state->connectors_changed = true;
 
 	DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d]\n",
 			 connector->base.id,
@@ -256,7 +256,8 @@ mode_fixup(struct drm_atomic_state *state)
 	bool ret;
 
 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
-		if (!crtc_state->mode_changed)
+		if (!crtc_state->mode_changed &&
+		    !crtc_state->connectors_changed)
 			continue;
 
 		drm_mode_copy(&crtc_state->adjusted_mode, &crtc_state->mode);
@@ -312,7 +313,8 @@ mode_fixup(struct drm_atomic_state *state)
 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
 		const struct drm_crtc_helper_funcs *funcs;
 
-		if (!crtc_state->mode_changed)
+		if (!crtc_state->mode_changed &&
+		    !crtc_state->connectors_changed)
 			continue;
 
 		funcs = crtc->helper_private;
@@ -373,7 +375,17 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
 		if (crtc->state->enable != crtc_state->enable) {
 			DRM_DEBUG_ATOMIC("[CRTC:%d] enable changed\n",
 					 crtc->base.id);
+
+			/*
+			 * For clarity this assignment is done here, but
+			 * enable == 0 is only true when there are no
+			 * connectors and a NULL mode.
+			 *
+			 * The other way around is true as well. enable != 0
+			 * iff connectors are attached and a mode is set.
+			 */
 			crtc_state->mode_changed = true;
+			crtc_state->connectors_changed = true;
 		}
 	}
 
@@ -2068,6 +2080,7 @@ void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
 	state->mode_changed = false;
 	state->active_changed = false;
 	state->planes_changed = false;
+	state->connectors_changed = false;
 	state->event = NULL;
 }
 EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 987eafed051c..bbd6ac8ba326 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -421,7 +421,7 @@ static const intel_limit_t intel_limits_bxt = {
 static bool
 needs_modeset(struct drm_crtc_state *state)
 {
-	return state->mode_changed || state->active_changed;
+	return drm_atomic_crtc_needs_modeset(state);
 }
 
 /**
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 8a3a913320eb..e67aeac2aee0 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -166,7 +166,8 @@ int __must_check drm_atomic_async_commit(struct drm_atomic_state *state);
 static inline bool
 drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state)
 {
-	return state->mode_changed || state->active_changed;
+	return state->mode_changed || state->active_changed ||
+	       state->connectors_changed;
 }
 
 
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 57ca8cc383a6..e39d6f1de5f7 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -255,12 +255,13 @@ struct drm_atomic_state;
  * @crtc: backpointer to the CRTC
  * @enable: whether the CRTC should be enabled, gates all other state
  * @active: whether the CRTC is actively displaying (used for DPMS)
- * @mode_changed: for use by helpers and drivers when computing state updates
- * @active_changed: for use by helpers and drivers when computing state updates
+ * @planes_changed: planes on this crtc are updated
+ * @mode_changed: crtc_state->mode or crtc_state->enable has been changed
+ * @active_changed: crtc_state->active
+ * @connectors_changed: connectors to this crtc have been updated
  * @plane_mask: bitmask of (1 << drm_plane_index(plane)) of attached planes
  * @last_vblank_count: for helpers and drivers to capture the vblank of the
  * 	update to ensure framebuffer cleanup isn't done too early
- * @planes_changed: for use by helpers and drivers when computing state updates
  * @adjusted_mode: for use by helpers and drivers to compute adjusted mode timings
  * @mode: current mode timings
  * @event: optional pointer to a DRM event to signal upon completion of the
@@ -283,6 +284,7 @@ struct drm_crtc_state {
 	bool planes_changed : 1;
 	bool mode_changed : 1;
 	bool active_changed : 1;
+	bool connectors_changed : 1;
 
 	/* attached planes bitmask:
 	 * WARNING: transitional helpers do not maintain plane_mask so
-- 
2.1.0