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.
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 --- drivers/gpu/drm/arc/arcpgu_crtc.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/arc/arcpgu_crtc.c b/drivers/gpu/drm/arc/arcpgu_crtc.c index d5ca0c280e68..c9f183b11df9 100644 --- a/drivers/gpu/drm/arc/arcpgu_crtc.c +++ b/drivers/gpu/drm/arc/arcpgu_crtc.c @@ -145,16 +145,17 @@ 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); + if (drm_crtc_vblank_get(crtc) == 0) + drm_crtc_arm_vblank_event(crtc, event); + else + drm_crtc_send_vblank_event(crtc, event); + spin_unlock_irq(&crtc->dev->event_lock); } }