On Fri, 2012-10-05 at 18:09 -0600, Rob Clark wrote:
> On Fri, Oct 5, 2012 at 5:41 PM, Imre Deak <imre.deak at intel.com> wrote:
> > On Fri, 2012-10-05 at 16:18 -0600, Rob Clark wrote:
> >> On Fri, Oct 5, 2012 at 7:37 AM, Imre Deak <imre.deak at intel.com> wrote:
> >> > diff --git a/drivers/gpu/drm/i915/intel_display.c
> >> > b/drivers/gpu/drm/i915/intel_display.c
> >> > index ab1ef15..056e810 100644
> >> > --- a/drivers/gpu/drm/i915/intel_display.c
> >> > +++ b/drivers/gpu/drm/i915/intel_display.c
> >> > @@ -6247,7 +6247,6 @@ static void do_intel_finish_page_flip(struct
> >> > drm_device *dev,
> >> > struct intel_unpin_work *work;
> >> > struct drm_i915_gem_object *obj;
> >> > struct drm_pending_vblank_event *e;
> >> > - struct timeval tvbl;
> >> > unsigned long flags;
> >> >
> >> > /* Ignore early vblank irqs */
> >> > @@ -6264,12 +6263,13 @@ static void do_intel_finish_page_flip(struct
> >> > drm_device *dev,
> >> > intel_crtc->unpin_work = NULL;
> >> >
> >> > if (work->event) {
> >> > - e = work->event;
> >> > - e->event.sequence = drm_vblank_count_and_time(dev,
> >> > intel_crtc->pipe, &tvbl);
> >> > -
> >> > - e->event.tv_sec = tvbl.tv_sec;
> >> > - e->event.tv_usec = tvbl.tv_usec;
> >> > + struct drm_vblank_time tvbl;
> >> > + u32 seq;
> >> >
> >> > + e = work->event;
> >> > + seq = drm_vblank_count_and_time(dev, intel_crtc->pipe,
> >> > &tvbl);
> >> > + drm_set_event_seq_and_time(&e->event, e->timestamp_raw,
> >> > seq,
> >> > + &tvbl);
> >> > list_add_tail(&e->base.link,
> >> > &e->base.file_priv->event_list);
> >> > wake_up_interruptible(&e->base.file_priv->event_wait);
> >>
> >>
> >> btw, I wonder if we could just have a helper like:
> >>
> >> int drm_send_page_flip_event(struct drm_device *dev, int crtc,
> >> struct drm_pending_vblank_event *event);
> >>
> >> Since most drivers have pretty much the same code for sending vblank
> >> event after a page flip..
> >>
> >> I guess not strictly related to monotonic timestamps, but it has been
> >> a cleanup that I've been meaning to do for a while.. and I guess if
> >> this was done first it wouldn't mean touching each driver (as much) to
> >> add support for monotonic timestamps.
> >
> > Good idea, we should do this.
> >
> > But if we want to reduce the diff from my changes then the proto should
> > rather be:
> >
> > int drm_send_page_flip_event(struct drm_device *dev, int crtc,
> > struct drm_pending_vblank_event *event,
> > int seq, struct timeval *now);
>
> do we need 'seq' and 'now'? I was sort of thinking that could all be
> internal to the send_page_flip_event() fxn.. ie. like:
>
> ---------
> void drm_send_page_flip_event(struct drm_device *dev, int pipe,
> struct drm_crtc *crtc, struct drm_pending_vblank_event *event)
> {
> struct timeval tnow, tvbl;
>
> do_gettimeofday(&tnow);
>
> event->event.sequence = drm_vblank_count_and_time(dev, pipe, &tvbl);
Ah, ok, you are right. I originally thought of using this helper in
drm_handle_vblank_events too, but now I realized it's not quite the same
sequence there.
>
> /* Called before vblank count and timestamps have
> * been updated for the vblank interval of flip
> * completion? Need to increment vblank count and
> * add one videorefresh duration to returned timestamp
> * to account for this. We assume this happened if we
> * get called over 0.9 frame durations after the last
> * timestamped vblank.
> *
> * This calculation can not be used with vrefresh rates
> * below 5Hz (10Hz to be on the safe side) without
> * promoting to 64 integers.
> */
> if (10 * (timeval_to_ns(&tnow) - timeval_to_ns(&tvbl)) >
> 9 * crtc->framedur_ns) {
> event->event.sequence++;
> tvbl = ns_to_timeval(timeval_to_ns(&tvbl) +
> crtc->framedur_ns);
> }
This has been recently removed by danvet's "drm/i915: don't frob the
vblank ts in finish_page_flip", though not yet committed, so we can do
away with it here too.
> event->event.tv_sec = tvbl.tv_sec;
> event->event.tv_usec = tvbl.tv_usec;
>
> list_add_tail(&event->base.link,
> &event->base.file_priv->event_list);
> wake_up_interruptible(&event->base.file_priv->event_wait);
> }
> ---------
>
> well, this would be the pre-monotonic timestamp version.. and it is a
> bit weird to have to pass in both crtc ptr and pipe #.. I don't see
> anything obvious in drm core that links pipe # and crtc ptr, although
> userspace seems to make this assumption about order of crtc's. But I
> think that if() statement is only in i915 driver.. I assume because
> you don't know if this will get called before or after
> drm_handle_vblank()? I guess that shouldn't hurt for other drivers.
>
> then each driver would just have something like:
>
> ---------
> if (work->event)
> drm_send_page_flip_event(dev, intel_crtc->pipe, crtc,
> work->event);
> ---------
>
>
> > with struct timeval changing to struct drm_vblank_time with my changes.
> >
> > I can do this if you agree - unless you have something ready.
>
> I've locally split out this into a helper fxn in omapdrm, but haven't
> got around to pushing it to core and updating other drivers. If you
> want I can send a patch, but I guess it is easier to just include
> something like this in your patchset. I'm ok either way.
I think the easiest is if you post your updated patch since it can be
anyway applied independently. I'll then rebase my changes on top of
that.
Thanks,
Imre
