From: Christopher James Halse Rogers christopher.halse.rogers@canonical.com
This is the least-bad behaviour. It means that we signal the vblank event before it actually happens, but since we're disabling vblanks there's no guarantee that it will *ever* happen otherwise.
This prevents GL applications which use WaitMSC from hanging indefinitely.
Signed-off-by: Christopher James Halse Rogers christopher.halse.rogers@canonical.com --- drivers/gpu/drm/drm_irq.c | 23 +++++++++++++++++++++++ 1 files changed, 23 insertions(+), 0 deletions(-)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 741457b..a1f12cb 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -932,11 +932,34 @@ EXPORT_SYMBOL(drm_vblank_put);
void drm_vblank_off(struct drm_device *dev, int crtc) { + struct drm_pending_vblank_event *e, *t; + struct timeval now; unsigned long irqflags; + unsigned int seq;
spin_lock_irqsave(&dev->vbl_lock, irqflags); vblank_disable_and_save(dev, crtc); DRM_WAKEUP(&dev->vbl_queue[crtc]); + + /* Send any queued vblank events, lest the natives grow disquiet */ + seq = drm_vblank_count_and_time(dev, crtc, &now); + list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) { + if (e->pipe != crtc) + continue; + DRM_DEBUG("Sending premature vblank event on disable: \ + wanted %d, current %d\n", + e->event.sequence, seq); + + e->event.sequence = seq; + e->event.tv_sec = now.tv_sec; + e->event.tv_usec = now.tv_usec; + drm_vblank_put(dev, e->pipe); + list_move_tail(&e->base.link, &e->base.file_priv->event_list); + wake_up_interruptible(&e->base.file_priv->event_wait); + trace_drm_vblank_event_delivered(e->base.pid, e->pipe, + e->event.sequence); + } + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); } EXPORT_SYMBOL(drm_vblank_off);