drm/i915: Use atomic state to obtain load detection crtc, v3.

Instead of restoring dpms and a flag for whether a temp fb is allocated duplicate
an atomic state before the new state is committed, and commit it the old state
in intel_release_load_detect_pipe.

Changes since v1:
- Use a real atomic state. (Ville)
Changes since v2:
- Do not preserve shared_dpll any more, no need to do so. (Ville)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455697119-31416-2-git-send-email-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -10366,6 +10366,7 @@ mode_fits_in_fbdev(struct drm_device *dev,
 	if (obj->base.size < mode->vdisplay * fb->pitches[0])
 		return NULL;
 
+	drm_framebuffer_reference(fb);
 	return fb;
 #else
 	return NULL;
@@ -10421,7 +10422,7 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 	struct drm_device *dev = encoder->dev;
 	struct drm_framebuffer *fb;
 	struct drm_mode_config *config = &dev->mode_config;
-	struct drm_atomic_state *state = NULL;
+	struct drm_atomic_state *state = NULL, *restore_state = NULL;
 	struct drm_connector_state *connector_state;
 	struct intel_crtc_state *crtc_state;
 	int ret, i = -1;
@@ -10430,6 +10431,8 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 		      connector->base.id, connector->name,
 		      encoder->base.id, encoder->name);
 
+	old->restore_state = NULL;
+
 retry:
 	ret = drm_modeset_lock(&config->connection_mutex, ctx);
 	if (ret)
@@ -10446,24 +10449,15 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 	 */
 
 	/* See if we already have a CRTC for this connector */
-	if (encoder->crtc) {
-		crtc = encoder->crtc;
+	if (connector->state->crtc) {
+		crtc = connector->state->crtc;
 
 		ret = drm_modeset_lock(&crtc->mutex, ctx);
-		if (ret)
-			goto fail;
-		ret = drm_modeset_lock(&crtc->primary->mutex, ctx);
 		if (ret)
 			goto fail;
 
-		old->dpms_mode = connector->dpms;
-		old->load_detect_temp = false;
-
 		/* Make sure the crtc and connector are running */
-		if (connector->dpms != DRM_MODE_DPMS_ON)
-			connector->funcs->dpms(connector, DRM_MODE_DPMS_ON);
-
-		return true;
+		goto found;
 	}
 
 	/* Find an unused one (if possible) */
@@ -10471,8 +10465,15 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 		i++;
 		if (!(encoder->possible_crtcs & (1 << i)))
 			continue;
-		if (possible_crtc->state->enable)
+
+		ret = drm_modeset_lock(&possible_crtc->mutex, ctx);
+		if (ret)
+			goto fail;
+
+		if (possible_crtc->state->enable) {
+			drm_modeset_unlock(&possible_crtc->mutex);
 			continue;
+		}
 
 		crtc = possible_crtc;
 		break;
@@ -10486,23 +10487,22 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 		goto fail;
 	}
 
-	ret = drm_modeset_lock(&crtc->mutex, ctx);
-	if (ret)
-		goto fail;
+found:
+	intel_crtc = to_intel_crtc(crtc);
+
 	ret = drm_modeset_lock(&crtc->primary->mutex, ctx);
 	if (ret)
 		goto fail;
 
-	intel_crtc = to_intel_crtc(crtc);
-	old->dpms_mode = connector->dpms;
-	old->load_detect_temp = true;
-	old->release_fb = NULL;
-
 	state = drm_atomic_state_alloc(dev);
-	if (!state)
-		return false;
+	restore_state = drm_atomic_state_alloc(dev);
+	if (!state || !restore_state) {
+		ret = -ENOMEM;
+		goto fail;
+	}
 
 	state->acquire_ctx = ctx;
+	restore_state->acquire_ctx = ctx;
 
 	connector_state = drm_atomic_get_connector_state(state, connector);
 	if (IS_ERR(connector_state)) {
@@ -10510,7 +10510,9 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 		goto fail;
 	}
 
-	connector_state->crtc = crtc;
+	ret = drm_atomic_set_crtc_for_connector(connector_state, crtc);
+	if (ret)
+		goto fail;
 
 	crtc_state = intel_atomic_get_crtc_state(state, intel_crtc);
 	if (IS_ERR(crtc_state)) {
@@ -10534,7 +10536,6 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 	if (fb == NULL) {
 		DRM_DEBUG_KMS("creating tmp fb for load-detection\n");
 		fb = intel_framebuffer_create_for_mode(dev, mode, 24, 32);
-		old->release_fb = fb;
 	} else
 		DRM_DEBUG_KMS("reusing fbdev for load-detection framebuffer\n");
 	if (IS_ERR(fb)) {
@@ -10546,15 +10547,28 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 	if (ret)
 		goto fail;
 
-	drm_mode_copy(&crtc_state->base.mode, mode);
+	drm_framebuffer_unreference(fb);
+
+	ret = drm_atomic_set_mode_for_crtc(&crtc_state->base, mode);
+	if (ret)
+		goto fail;
+
+	ret = PTR_ERR_OR_ZERO(drm_atomic_get_connector_state(restore_state, connector));
+	if (!ret)
+		ret = PTR_ERR_OR_ZERO(drm_atomic_get_crtc_state(restore_state, crtc));
+	if (!ret)
+		ret = PTR_ERR_OR_ZERO(drm_atomic_get_plane_state(restore_state, crtc->primary));
+	if (ret) {
+		DRM_DEBUG_KMS("Failed to create a copy of old state to restore: %i\n", ret);
+		goto fail;
+	}
 
 	if (drm_atomic_commit(state)) {
 		DRM_DEBUG_KMS("failed to set mode on load-detect pipe\n");
-		if (old->release_fb)
-			old->release_fb->funcs->destroy(old->release_fb);
 		goto fail;
 	}
-	crtc->primary->crtc = crtc;
+
+	old->restore_state = restore_state;
 
 	/* let the connector get through one full cycle before testing */
 	intel_wait_for_vblank(dev, intel_crtc->pipe);
@@ -10562,7 +10576,8 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector,
 
 fail:
 	drm_atomic_state_free(state);
-	state = NULL;
+	drm_atomic_state_free(restore_state);
+	restore_state = state = NULL;
 
 	if (ret == -EDEADLK) {
 		drm_modeset_backoff(ctx);
@@ -10576,65 +10591,24 @@ void intel_release_load_detect_pipe(struct drm_connector *connector,
 				    struct intel_load_detect_pipe *old,
 				    struct drm_modeset_acquire_ctx *ctx)
 {
-	struct drm_device *dev = connector->dev;
 	struct intel_encoder *intel_encoder =
 		intel_attached_encoder(connector);
 	struct drm_encoder *encoder = &intel_encoder->base;
-	struct drm_crtc *crtc = encoder->crtc;
-	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
-	struct drm_atomic_state *state;
-	struct drm_connector_state *connector_state;
-	struct intel_crtc_state *crtc_state;
+	struct drm_atomic_state *state = old->restore_state;
 	int ret;
 
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s], [ENCODER:%d:%s]\n",
 		      connector->base.id, connector->name,
 		      encoder->base.id, encoder->name);
 
-	if (old->load_detect_temp) {
-		state = drm_atomic_state_alloc(dev);
 	if (!state)
-			goto fail;
-
-		state->acquire_ctx = ctx;
-
-		connector_state = drm_atomic_get_connector_state(state, connector);
-		if (IS_ERR(connector_state))
-			goto fail;
-
-		crtc_state = intel_atomic_get_crtc_state(state, intel_crtc);
-		if (IS_ERR(crtc_state))
-			goto fail;
-
-		connector_state->crtc = NULL;
-
-		crtc_state->base.enable = crtc_state->base.active = false;
-
-		ret = intel_modeset_setup_plane_state(state, crtc, NULL, NULL,
-						      0, 0);
-		if (ret)
-			goto fail;
-
-		ret = drm_atomic_commit(state);
-		if (ret)
-			goto fail;
-
-		if (old->release_fb) {
-			drm_framebuffer_unregister_private(old->release_fb);
-			drm_framebuffer_unreference(old->release_fb);
-		}
-
 		return;
-	}
 
-	/* Switch crtc and encoder back off if necessary */
-	if (old->dpms_mode != DRM_MODE_DPMS_ON)
-		connector->funcs->dpms(connector, old->dpms_mode);
-
-	return;
-fail:
-	DRM_DEBUG_KMS("Couldn't release load detect pipe.\n");
+	ret = drm_atomic_commit(state);
+	if (ret) {
+		DRM_DEBUG_KMS("Couldn't release load detect pipe: %i\n", ret);
 		drm_atomic_state_free(state);
+	}
 }
 
 static int i9xx_pll_refclk(struct drm_device *dev,

drivers/gpu/drm/i915/intel_drv.h

@@ -910,9 +910,7 @@ struct intel_unpin_work {
 };
 
 struct intel_load_detect_pipe {
-	struct drm_framebuffer *release_fb;
-	bool load_detect_temp;
-	int dpms_mode;
+	struct drm_atomic_state *restore_state;
 };
 
 static inline struct intel_encoder *