drm/fb-helper: atomic restore_fbdev_mode()..

Add support for using atomic code-paths for restore_fbdev_mode().
Signed-off-by: Rob Clark <robdclark@gmail.com>
[danvet: Bikeshed comments slightly.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_atomic_helper.c

@@ -1553,21 +1553,9 @@ int drm_atomic_helper_disable_plane(struct drm_plane *plane)
 		goto fail;
 	}
 
-	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+	ret = __drm_atomic_helper_disable_plane(plane, plane_state);
 	if (ret != 0)
 		goto fail;
-	drm_atomic_set_fb_for_plane(plane_state, NULL);
-	plane_state->crtc_x = 0;
-	plane_state->crtc_y = 0;
-	plane_state->crtc_h = 0;
-	plane_state->crtc_w = 0;
-	plane_state->src_x = 0;
-	plane_state->src_y = 0;
-	plane_state->src_h = 0;
-	plane_state->src_w = 0;
-
-	if (plane == plane->crtc->cursor)
-		state->legacy_cursor_update = true;
 
 	ret = drm_atomic_commit(state);
 	if (ret != 0)
@@ -1597,6 +1585,32 @@ int drm_atomic_helper_disable_plane(struct drm_plane *plane)
 }
 EXPORT_SYMBOL(drm_atomic_helper_disable_plane);
 
+/* just used from fb-helper and atomic-helper: */
+int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
+		struct drm_plane_state *plane_state)
+{
+	int ret;
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+	if (ret != 0)
+		return ret;
+
+	drm_atomic_set_fb_for_plane(plane_state, NULL);
+	plane_state->crtc_x = 0;
+	plane_state->crtc_y = 0;
+	plane_state->crtc_h = 0;
+	plane_state->crtc_w = 0;
+	plane_state->src_x = 0;
+	plane_state->src_y = 0;
+	plane_state->src_h = 0;
+	plane_state->src_w = 0;
+
+	if (plane->crtc && (plane == plane->crtc->cursor))
+		plane_state->state->legacy_cursor_update = true;
+
+	return 0;
+}
+
 static int update_output_state(struct drm_atomic_state *state,
 			       struct drm_mode_set *set)
 {
@@ -1680,8 +1694,6 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
 {
 	struct drm_atomic_state *state;
 	struct drm_crtc *crtc = set->crtc;
-	struct drm_crtc_state *crtc_state;
-	struct drm_plane_state *primary_state;
 	int ret = 0;
 
 	state = drm_atomic_state_alloc(crtc->dev);
@@ -1690,17 +1702,54 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
 
 	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
 retry:
-	crtc_state = drm_atomic_get_crtc_state(state, crtc);
-	if (IS_ERR(crtc_state)) {
-		ret = PTR_ERR(crtc_state);
+	ret = __drm_atomic_helper_set_config(set, state);
+	if (ret != 0)
 		goto fail;
-	}
 
-	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
-	if (IS_ERR(primary_state)) {
-		ret = PTR_ERR(primary_state);
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
 		goto fail;
-	}
+
+	/* Driver takes ownership of state on successful commit. */
+	return 0;
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	/*
+	 * Someone might have exchanged the framebuffer while we dropped locks
+	 * in the backoff code. We need to fix up the fb refcount tracking the
+	 * core does for us.
+	 */
+	crtc->primary->old_fb = crtc->primary->fb;
+
+	goto retry;
+}
+EXPORT_SYMBOL(drm_atomic_helper_set_config);
+
+/* just used from fb-helper and atomic-helper: */
+int __drm_atomic_helper_set_config(struct drm_mode_set *set,
+		struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_plane_state *primary_state;
+	struct drm_crtc *crtc = set->crtc;
+	int ret;
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state))
+		return PTR_ERR(crtc_state);
+
+	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
+	if (IS_ERR(primary_state))
+		return PTR_ERR(primary_state);
 
 	if (!set->mode) {
 		WARN_ON(set->fb);
@@ -1708,13 +1757,13 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
 
 		ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
 		if (ret != 0)
-			goto fail;
+			return ret;
 
 		crtc_state->active = false;
 
 		ret = drm_atomic_set_crtc_for_plane(primary_state, NULL);
 		if (ret != 0)
-			goto fail;
+			return ret;
 
 		drm_atomic_set_fb_for_plane(primary_state, NULL);
 
@@ -1726,13 +1775,14 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
 
 	ret = drm_atomic_set_mode_for_crtc(crtc_state, set->mode);
 	if (ret != 0)
-		goto fail;
+		return ret;
 
 	crtc_state->active = true;
 
 	ret = drm_atomic_set_crtc_for_plane(primary_state, crtc);
 	if (ret != 0)
-		goto fail;
+		return ret;
+
 	drm_atomic_set_fb_for_plane(primary_state, set->fb);
 	primary_state->crtc_x = 0;
 	primary_state->crtc_y = 0;
@@ -1746,35 +1796,10 @@ int drm_atomic_helper_set_config(struct drm_mode_set *set)
 commit:
 	ret = update_output_state(state, set);
 	if (ret)
-		goto fail;
-
-	ret = drm_atomic_commit(state);
-	if (ret != 0)
-		goto fail;
+		return ret;
 
-	/* Driver takes ownership of state on successful commit. */
 	return 0;
-fail:
-	if (ret == -EDEADLK)
-		goto backoff;
-
-	drm_atomic_state_free(state);
-
-	return ret;
-backoff:
-	drm_atomic_state_clear(state);
-	drm_atomic_legacy_backoff(state);
-
-	/*
-	 * Someone might have exchanged the framebuffer while we dropped locks
-	 * in the backoff code. We need to fix up the fb refcount tracking the
-	 * core does for us.
-	 */
-	crtc->primary->old_fb = crtc->primary->fb;
-
-	goto retry;
 }
-EXPORT_SYMBOL(drm_atomic_helper_set_config);
 
 /**
  * drm_atomic_helper_crtc_set_property - helper for crtc properties

drivers/gpu/drm/drm_fb_helper.c

@@ -38,6 +38,8 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
 
 static bool drm_fbdev_emulation = true;
 module_param_named(fbdev_emulation, drm_fbdev_emulation, bool, 0600);
@@ -334,6 +336,72 @@ int drm_fb_helper_debug_leave(struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
 
+static int restore_fbdev_mode_atomic(struct drm_fb_helper *fb_helper)
+{
+	struct drm_device *dev = fb_helper->dev;
+	struct drm_plane *plane;
+	struct drm_atomic_state *state;
+	int i, ret;
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = dev->mode_config.acquire_ctx;
+retry:
+	drm_for_each_plane(plane, dev) {
+		struct drm_plane_state *plane_state;
+
+		plane_state = drm_atomic_get_plane_state(state, plane);
+		if (IS_ERR(plane_state)) {
+			ret = PTR_ERR(plane_state);
+			goto fail;
+		}
+
+		ret = drm_atomic_plane_set_property(plane, plane_state,
+				dev->mode_config.rotation_property,
+				BIT(DRM_ROTATE_0));
+		if (ret != 0)
+			goto fail;
+
+		/* disable non-primary: */
+		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
+			continue;
+
+		ret = __drm_atomic_helper_disable_plane(plane, plane_state);
+		if (ret != 0)
+			goto fail;
+	}
+
+	for(i = 0; i < fb_helper->crtc_count; i++) {
+		struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
+
+		ret = __drm_atomic_helper_set_config(mode_set, state);
+		if (ret != 0)
+			goto fail;
+	}
+
+	ret = drm_atomic_commit(state);
+	if (ret != 0)
+		goto fail;
+
+	return 0;
+
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
+	drm_atomic_state_free(state);
+
+	return ret;
+
+backoff:
+	drm_atomic_state_clear(state);
+	drm_atomic_legacy_backoff(state);
+
+	goto retry;
+}
+
 static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 {
 	struct drm_device *dev = fb_helper->dev;
@@ -342,6 +410,9 @@ static int restore_fbdev_mode(struct drm_fb_helper *fb_helper)
 
 	drm_warn_on_modeset_not_all_locked(dev);
 
+	if (fb_helper->atomic)
+		return restore_fbdev_mode_atomic(fb_helper);
+
 	drm_for_each_plane(plane, dev) {
 		if (plane->type != DRM_PLANE_TYPE_PRIMARY)
 			drm_plane_force_disable(plane);
@@ -644,6 +715,8 @@ int drm_fb_helper_init(struct drm_device *dev,
 		i++;
 	}
 
+	fb_helper->atomic = !!drm_core_check_feature(dev, DRIVER_ATOMIC);
+
 	return 0;
 out_free:
 	drm_fb_helper_crtc_free(fb_helper);

include/drm/drm_atomic_helper.h

@@ -30,6 +30,8 @@
 
 #include <drm/drm_crtc.h>
 
+struct drm_atomic_state;
+
 int drm_atomic_helper_check_modeset(struct drm_device *dev,
 				struct drm_atomic_state *state);
 int drm_atomic_helper_check_planes(struct drm_device *dev,
@@ -73,7 +75,11 @@ int drm_atomic_helper_update_plane(struct drm_plane *plane,
 				   uint32_t src_x, uint32_t src_y,
 				   uint32_t src_w, uint32_t src_h);
 int drm_atomic_helper_disable_plane(struct drm_plane *plane);
+int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
+		struct drm_plane_state *plane_state);
 int drm_atomic_helper_set_config(struct drm_mode_set *set);
+int __drm_atomic_helper_set_config(struct drm_mode_set *set,
+		struct drm_atomic_state *state);
 
 int drm_atomic_helper_crtc_set_property(struct drm_crtc *crtc,
 					struct drm_property *property,

include/drm/drm_fb_helper.h

@@ -134,6 +134,17 @@ struct drm_fb_helper {
 	/* we got a hotplug but fbdev wasn't running the console
 	   delay until next set_par */
 	bool delayed_hotplug;
+
+	/**
+	 * @atomic:
+	 *
+	 * Use atomic updates for restore_fbdev_mode(), etc.  This defaults to
+	 * true if driver has DRIVER_ATOMIC feature flag, but drivers can
+	 * override it to true after drm_fb_helper_init() if they support atomic
+	 * modeset but do not yet advertise DRIVER_ATOMIC (note that fb-helper
+	 * does not require ASYNC commits).
+	 */
+	bool atomic;
 };
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION