drm/arc: Actually bother with handling atomic events.

The drm core has a nice ready-made helper for exactly the simple case
where it should fire on the next vblank.

Note that arming the vblank event in _begin is probably too early, and
might easily result in the vblank firing too early, before the new set
of planes are actually disabled. But that's kinda a minor issue
compared to just outright hanging userspace.

v2: Be more robust and either arm, when the CRTC is on, or just send
the event out right away.

v3: Just unconditionally send out the event directly, for safety -
arcpgu doesn't even have vblank support ...

Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-3-git-send-email-daniel.vetter@ffwll.ch
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-4-git-send-email-daniel.vetter@ffwll.ch

diff --git a/drivers/gpu/drm/arc/arcpgu_crtc.c b/drivers/gpu/drm/arc/arcpgu_crtc.c
index d5ca0c2..ee0a61c 100644 (file)
--- a/drivers/gpu/drm/arc/arcpgu_crtc.c
+++ b/drivers/gpu/drm/arc/arcpgu_crtc.c
@@ -145,16 +145,14 @@ static int arc_pgu_crtc_atomic_check(struct drm_crtc *crtc,
 static void arc_pgu_crtc_atomic_begin(struct drm_crtc *crtc,
                                      struct drm_crtc_state *state)
 {
-       struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
-       unsigned long flags;
-
-       if (crtc->state->event) {
-               struct drm_pending_vblank_event *event = crtc->state->event;
+       struct drm_pending_vblank_event *event = crtc->state->event;
 
+       if (event) {
                crtc->state->event = NULL;
-               event->pipe = drm_crtc_index(crtc);
 
-               WARN_ON(drm_crtc_vblank_get(crtc) != 0);
+               spin_lock_irq(&crtc->dev->event_lock);
+               drm_crtc_send_vblank_event(crtc, event);
+               spin_unlock_irq(&crtc->dev->event_lock);
        }
 }