drm/sti: Store correct CRTC index in events

A negative pipe causes a special case to be triggered for drivers that
don't have proper VBLANK support. STi does support VBLANKs, so there is
no need for the fallback code.

Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Vincent Abriou <vincent.abriou@st.com>

drivers/gpu/drm/sti/sti_crtc.c

@@ -274,7 +274,7 @@ int sti_crtc_vblank_cb(struct notifier_block *nb,
 
 	spin_lock_irqsave(&drm_dev->event_lock, flags);
 	if (compo->mixer[*crtc]->pending_event) {
-		drm_send_vblank_event(drm_dev, -1,
+		drm_send_vblank_event(drm_dev, *crtc,
 				      compo->mixer[*crtc]->pending_event);
 		drm_vblank_put(drm_dev, *crtc);
 		compo->mixer[*crtc]->pending_event = NULL;