Make crtc_notify wrap/unwrap code do nothing unless mode code is inuse

Drivers not using the new hw/xfree86/modes code would crash in DRI due to
that code trying to monitor CRTC changes.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 18 insertions, 11 deletions

diff --git a/hw/xfree86/modes/xf86Crtc.c b/hw/xfree86/modes/xf86Crtc.c
index cb13debb3..217e01c75 100644
--- a/hw/xfree86/modes/xf86Crtc.c
+++ b/hw/xfree86/modes/xf86Crtc.c
@@ -3117,22 +3117,29 @@ xf86_crtc_clip_video_helper(ScrnInfoPtr pScrn,
 xf86_crtc_notify_proc_ptr
 xf86_wrap_crtc_notify (ScreenPtr screen, xf86_crtc_notify_proc_ptr new)
 {
-    ScrnInfoPtr         scrn = xf86Screens[screen->myNum];
-    xf86CrtcConfigPtr   config = XF86_CRTC_CONFIG_PTR(scrn);
-    xf86_crtc_notify_proc_ptr   old;
-    
-    old = config->xf86_crtc_notify;
-    config->xf86_crtc_notify = new;
-    return old;
+    if (xf86CrtcConfigPrivateIndex != -1)
+    {
+        ScrnInfoPtr             scrn = xf86Screens[screen->myNum];
+        xf86CrtcConfigPtr       config = XF86_CRTC_CONFIG_PTR(scrn);
+        xf86_crtc_notify_proc_ptr       old;
+        
+        old = config->xf86_crtc_notify;
+        config->xf86_crtc_notify = new;
+        return old;
+    }
+    return NULL;
 }
 
 void
 xf86_unwrap_crtc_notify(ScreenPtr screen, xf86_crtc_notify_proc_ptr old)
 {
-    ScrnInfoPtr         scrn = xf86Screens[screen->myNum];
-    xf86CrtcConfigPtr   config = XF86_CRTC_CONFIG_PTR(scrn);
-
-    config->xf86_crtc_notify = old;
+    if (xf86CrtcConfigPrivateIndex != -1)
+    {
+        ScrnInfoPtr             scrn = xf86Screens[screen->myNum];
+        xf86CrtcConfigPtr       config = XF86_CRTC_CONFIG_PTR(scrn);
+    
+        config->xf86_crtc_notify = old;
+    }
 }
 
 void