drm/atomic-helper: Add NO_DISABLE_AFTER_MODESET flag support for plane commit

Drivers may set the NO_DISABLE_AFTER_MODESET flag in the 'flags' parameter
of the helper drm_atomic_helper_commit_planes() if the relevant display
controllers(e.g., IPUv3 for imx-drm) require to disable a CRTC's planes
when the CRTC is disabled. The helper would skip the ->atomic_disable
call for a plane if the CRTC of the old plane state needs a modesetting
operation. Of course, the drivers need to disable the planes in their CRTC
disable callbacks since no one else would do that.

Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Liu Ying <gnuiyl@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1472461923-14364-1-git-send-email-gnuiyl@gmail.com

1 files changed, 31 insertions, 12 deletions

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 5f82290f2f0f..6fdd7ba47896 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1148,7 +1148,8 @@ EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks);
  *
  *     drm_atomic_helper_commit_modeset_enables(dev, state);
  *
- *     drm_atomic_helper_commit_planes(dev, state, true);
+ *     drm_atomic_helper_commit_planes(dev, state,
+ *                                     DRM_PLANE_COMMIT_ACTIVE_ONLY);
  *
  * for committing the atomic update to hardware.  See the kerneldoc entries for
  * these three functions for more details.
@@ -1159,7 +1160,7 @@ void drm_atomic_helper_commit_tail(struct drm_atomic_state *state)
 
 	drm_atomic_helper_commit_modeset_disables(dev, state);
 
-	drm_atomic_helper_commit_planes(dev, state, false);
+	drm_atomic_helper_commit_planes(dev, state, 0);
 
 	drm_atomic_helper_commit_modeset_enables(dev, state);
 
@@ -1678,7 +1679,7 @@ bool plane_crtc_active(struct drm_plane_state *state)
  * drm_atomic_helper_commit_planes - commit plane state
  * @dev: DRM device
  * @old_state: atomic state object with old state structures
- * @active_only: Only commit on active CRTC if set
+ * @flags: flags for committing plane state
  *
  * This function commits the new plane state using the plane and atomic helper
  * functions for planes and crtcs. It assumes that the atomic state has already
@@ -1698,25 +1699,34 @@ bool plane_crtc_active(struct drm_plane_state *state)
  * most drivers don't need to be immediately notified of plane updates for a
  * disabled CRTC.
  *
- * Unless otherwise needed, drivers are advised to set the @active_only
- * parameters to true in order not to receive plane update notifications related
- * to a disabled CRTC. This avoids the need to manually ignore plane updates in
+ * Unless otherwise needed, drivers are advised to set the ACTIVE_ONLY flag in
+ * @flags in order not to receive plane update notifications related to a
+ * disabled CRTC. This avoids the need to manually ignore plane updates in
  * driver code when the driver and/or hardware can't or just don't need to deal
  * with updates on disabled CRTCs, for example when supporting runtime PM.
  *
- * The drm_atomic_helper_commit() default implementation only sets @active_only
- * to false to most closely match the behaviour of the legacy helpers. This should
- * not be copied blindly by drivers.
+ * Drivers may set the NO_DISABLE_AFTER_MODESET flag in @flags if the relevant
+ * display controllers require to disable a CRTC's planes when the CRTC is
+ * disabled. This function would skip the ->atomic_disable call for a plane if
+ * the CRTC of the old plane state needs a modesetting operation. Of course,
+ * the drivers need to disable the planes in their CRTC disable callbacks
+ * since no one else would do that.
+ *
+ * The drm_atomic_helper_commit() default implementation doesn't set the
+ * ACTIVE_ONLY flag to most closely match the behaviour of the legacy helpers.
+ * This should not be copied blindly by drivers.
  */
 void drm_atomic_helper_commit_planes(struct drm_device *dev,
 				     struct drm_atomic_state *old_state,
-				     bool active_only)
+				     uint32_t flags)
 {
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *old_crtc_state;
 	struct drm_plane *plane;
 	struct drm_plane_state *old_plane_state;
 	int i;
+	bool active_only = flags & DRM_PLANE_COMMIT_ACTIVE_ONLY;
+	bool no_disable = flags & DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET;
 
 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
 		const struct drm_crtc_helper_funcs *funcs;
@@ -1760,10 +1770,19 @@ void drm_atomic_helper_commit_planes(struct drm_device *dev,
 		/*
 		 * Special-case disabling the plane if drivers support it.
 		 */
-		if (disabling && funcs->atomic_disable)
+		if (disabling && funcs->atomic_disable) {
+			struct drm_crtc_state *crtc_state;
+
+			crtc_state = old_plane_state->crtc->state;
+
+			if (drm_atomic_crtc_needs_modeset(crtc_state) &&
+			    no_disable)
+				continue;
+
 			funcs->atomic_disable(plane, old_plane_state);
-		else if (plane->state->crtc || disabling)
+		} else if (plane->state->crtc || disabling) {
 			funcs->atomic_update(plane, old_plane_state);
+		}
 	}
 
 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {