From 75cff0837c14eaf632efabb8d7ab9eec6394d20d Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 24 Mar 2017 17:30:58 +0000 Subject: [PATCH] drm: Make the decision to keep vblank irq enabled earlier MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We want to provide the vblank irq shadow for pageflip events as well as vblank queries. Such events are completed within the vblank interrupt handler, and so the current check for disabling the irq will disable it from with the same interrupt as the last pageflip event. If we move the decision on whether to disable the irq (based on there no being no remaining vblank events, i.e. vblank->refcount == 0) to before we signal the events, we will only disable the irq on the interrupt after the last event was signaled. In the normal course of events, this will keep the vblank irq enabled for the entire flip sequence whereas before it would flip-flop around every interrupt. v2: Move the disable_fn() call outside of the vblank_event_lock. Signed-off-by: Chris Wilson Cc: Ville Syrjälä Cc: Daniel Vetter Cc: Michel Dänzer Cc: Laurent Pinchart Cc: Dave Airlie , Cc: Mario Kleiner Reviewed-by: Ville Syrjälä #v1 Reviewed-by: Mario Kleiner #v1 Signed-off-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/20170324173058.23051-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/drm_irq.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 4b0c7475ed13..290e65b93a65 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1699,6 +1699,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) { struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; unsigned long irqflags; + bool disable_irq; if (WARN_ON_ONCE(!dev->num_crtcs)) return false; @@ -1726,20 +1727,23 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) spin_unlock(&dev->vblank_time_lock); wake_up(&vblank->queue); - drm_handle_vblank_events(dev, pipe); /* With instant-off, we defer disabling the interrupt until after - * we finish processing the following vblank. The disable has to - * be last (after drm_handle_vblank_events) so that the timestamp - * is always accurate. + * we finish processing the following vblank after all events have + * been signaled. The disable has to be last (after + * drm_handle_vblank_events) so that the timestamp is always accurate. */ - if (dev->vblank_disable_immediate && - drm_vblank_offdelay > 0 && - !atomic_read(&vblank->refcount)) - vblank_disable_fn((unsigned long)vblank); + disable_irq = (dev->vblank_disable_immediate && + drm_vblank_offdelay > 0 && + !atomic_read(&vblank->refcount)); + + drm_handle_vblank_events(dev, pipe); spin_unlock_irqrestore(&dev->event_lock, irqflags); + if (disable_irq) + vblank_disable_fn((unsigned long)vblank); + return true; } EXPORT_SYMBOL(drm_handle_vblank); -- 2.20.1