From 9cecbc2260daca7fcff45c735c4855242eff3765 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Sat, 17 Jul 2010 20:23:26 +0100
Subject: [PATCH] --- yaml --- r: 204998 b: refs/heads/master c:
 90c1efdd121c84ee73e9960667229a662f2315a3 h: refs/heads/master v: v3

---
 [refs]                           | 2 +-
 trunk/drivers/gpu/drm/drm_crtc.c | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 8a6c5f7dbc91..317d4c22e37e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 92897b5c669f5e819ff2596fe6228ca2e4904981
+refs/heads/master: 90c1efdd121c84ee73e9960667229a662f2315a3
diff --git a/trunk/drivers/gpu/drm/drm_crtc.c b/trunk/drivers/gpu/drm/drm_crtc.c
index d8d65f4232a9..4c68f76993d8 100644
--- a/trunk/drivers/gpu/drm/drm_crtc.c
+++ b/trunk/drivers/gpu/drm/drm_crtc.c
@@ -2617,6 +2617,15 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
 		goto out;
 	crtc = obj_to_crtc(obj);
 
+	if (crtc->fb == NULL) {
+		/* The framebuffer is currently unbound, presumably
+		 * due to a hotplug event, that userspace has not
+		 * yet discovered.
+		 */
+		ret = -EBUSY;
+		goto out;
+	}
+
 	if (crtc->funcs->page_flip == NULL)
 		goto out;