drm/atomic: Unify conflicting encoder handling.

Currently we use a flag to change behavior in atomic commit
whether a conflicting encoder should be enabled or disabled.
This is used for the legacy set_config helper, which disables
connectors that have a conflicting encoder but not part of the
active crtc list.

There's no need for this to be handled in atomic commit, it
could be done in the set_config helper instead. This will
let the atomic check function reject any conflicting encoders,
while set_config can disable conflicting crtc's. This makes it
possible to recalculate the changed flags in 1 loop.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1491477543-31257-2-git-send-email-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/drm_atomic_helper.c

@@ -517,7 +517,7 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
 		}
 	}
 
-	ret = handle_conflicting_encoders(state, state->legacy_set_config);
+	ret = handle_conflicting_encoders(state, false);
 	if (ret)
 		return ret;
 
@@ -2289,12 +2289,15 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set,
 	if (!state)
 		return -ENOMEM;
 
-	state->legacy_set_config = true;
 	state->acquire_ctx = ctx;
 	ret = __drm_atomic_helper_set_config(set, state);
 	if (ret != 0)
 		goto fail;
 
+	ret = handle_conflicting_encoders(state, true);
+	if (ret)
+		return ret;
+
 	ret = drm_atomic_commit(state);
 
 fail:

include/drm/drm_atomic.h

@@ -160,7 +160,6 @@ struct __drm_connnectors_state {
  * @dev: parent DRM device
  * @allow_modeset: allow full modeset
  * @legacy_cursor_update: hint to enforce legacy cursor IOCTL semantics
- * @legacy_set_config: Disable conflicting encoders instead of failing with -EINVAL.
  * @planes: pointer to array of structures with per-plane data
  * @crtcs: pointer to array of CRTC pointers
  * @num_connector: size of the @connectors and @connector_states arrays
@@ -173,7 +172,6 @@ struct drm_atomic_state {
 	struct drm_device *dev;
 	bool allow_modeset : 1;
 	bool legacy_cursor_update : 1;
-	bool legacy_set_config : 1;
 	struct __drm_planes_state *planes;
 	struct __drm_crtcs_state *crtcs;
 	int num_connector;