On Mon, Feb 20, 2023 at 1:08 AM Pekka Paalanen <ppaalanen@xxxxxxxxx> wrote:
>
> On Sat, 18 Feb 2023 13:15:53 -0800
> Rob Clark <robdclark@xxxxxxxxx> wrote:
>
> > From: Rob Clark <robdclark@xxxxxxxxxxxx>
> >
> > Will be used in the next commit to set a deadline on fences that an
> > atomic update is waiting on.
> >
> > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/drm_vblank.c | 32 ++++++++++++++++++++++++++++++++
> > include/drm/drm_vblank.h | 1 +
> > 2 files changed, 33 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> > index 2ff31717a3de..caf25ebb34c5 100644
> > --- a/drivers/gpu/drm/drm_vblank.c
> > +++ b/drivers/gpu/drm/drm_vblank.c
> > @@ -980,6 +980,38 @@ u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
> > }
> > EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
> >
> > +/**
> > + * drm_crtc_next_vblank_time - calculate the time of the next vblank
> > + * @crtc: the crtc for which to calculate next vblank time
> > + * @vblanktime: pointer to time to receive the next vblank timestamp.
> > + *
> > + * Calculate the expected time of the next vblank based on time of previous
> > + * vblank and frame duration
>
> Hi,
>
> for VRR this targets the highest frame rate possible for the current
> VRR mode, right?
>
It is based on vblank->framedur_ns which is in turn based on
mode->crtc_clock. Presumably for VRR that ends up being a maximum?
BR,
-R
>
> Thanks,
> pq
>
> > + */
> > +int drm_crtc_next_vblank_time(struct drm_crtc *crtc, ktime_t *vblanktime)
> > +{
> > + unsigned int pipe = drm_crtc_index(crtc);
> > + struct drm_vblank_crtc *vblank = &crtc->dev->vblank[pipe];
> > + u64 count;
> > +
> > + if (!vblank->framedur_ns)
> > + return -EINVAL;
> > +
> > + count = drm_vblank_count_and_time(crtc->dev, pipe, vblanktime);
> > +
> > + /*
> > + * If we don't get a valid count, then we probably also don't
> > + * have a valid time:
> > + */
> > + if (!count)
> > + return -EINVAL;
> > +
> > + *vblanktime = ktime_add(*vblanktime, ns_to_ktime(vblank->framedur_ns));
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL(drm_crtc_next_vblank_time);
> > +
> > static void send_vblank_event(struct drm_device *dev,
> > struct drm_pending_vblank_event *e,
> > u64 seq, ktime_t now)
> > diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h
> > index 733a3e2d1d10..a63bc2c92f3c 100644
> > --- a/include/drm/drm_vblank.h
> > +++ b/include/drm/drm_vblank.h
> > @@ -230,6 +230,7 @@ bool drm_dev_has_vblank(const struct drm_device *dev);
> > u64 drm_crtc_vblank_count(struct drm_crtc *crtc);
> > u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
> > ktime_t *vblanktime);
> > +int drm_crtc_next_vblank_time(struct drm_crtc *crtc, ktime_t *vblanktime);
> > void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
> > struct drm_pending_vblank_event *e);
> > void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
>
