On Tue, Jun 10, 2014 at 02:41:20PM +0300, Ville Syrjälä wrote: > On Tue, Jun 10, 2014 at 11:04:02AM +0100, Chris Wilson wrote: > > If we hit a vblank and see that have a pageflip queue but not yet > > processed, ensure that the GPU is running at maximum in order to clear > > the backlog. Pageflips are only queued for the following vblank, if we > > miss it, there will be a visible stutter. Boosting the GPU frequency > > doesn't prevent us from missing the target vblank, but it should help > > the subsequent frames hitting theirs. > > > > v2: Reorder vblank vs flip-complete so that we only check for a missed > > flip after processing the completion events, and avoid spurious boosts. > > > > v3: Rename missed_vblank > > > > Signed-off-by: Chris Wilson <[email protected]> > > Cc: Daniel Vetter <[email protected]> > > Cc: Ville Syrjälä <[email protected]> > > --- > > drivers/gpu/drm/i915/i915_drv.h | 1 + > > drivers/gpu/drm/i915/intel_display.c | 6 ++++++ > > drivers/gpu/drm/i915/intel_drv.h | 1 + > > drivers/gpu/drm/i915/intel_pm.c | 15 +++++++++++++++ > > 4 files changed, 23 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h > > b/drivers/gpu/drm/i915/i915_drv.h > > index 10dd80a..33ed0c6 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.h > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > @@ -910,6 +910,7 @@ struct intel_gen6_power_mgmt { > > > > bool enabled; > > struct delayed_work delayed_resume_work; > > + struct work_struct boost_work; > > > > /* > > * Protects RPS/RC6 register access and PCU communication. > > diff --git a/drivers/gpu/drm/i915/intel_display.c > > b/drivers/gpu/drm/i915/intel_display.c > > index 9ecc6bf..aeb58fa 100644 > > --- a/drivers/gpu/drm/i915/intel_display.c > > +++ b/drivers/gpu/drm/i915/intel_display.c > > @@ -9339,6 +9339,7 @@ void intel_check_page_flip(struct drm_device *dev, > > int pipe) > > struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe]; > > struct intel_crtc *intel_crtc = to_intel_crtc(crtc); > > unsigned long flags; > > + bool missed_vblank; > > > > if (crtc == NULL) > > return; > > @@ -9349,7 +9350,12 @@ void intel_check_page_flip(struct drm_device *dev, > > int pipe) > > intel_crtc->unpin_work->sbc, crtc_sbc(intel_crtc)); > > page_flip_completed(intel_crtc); > > } > > + missed_vblank = (intel_crtc->unpin_work != NULL && > > + crtc_sbc(intel_crtc) - intel_crtc->unpin_work->sbc > > > 1); > > So this will boost when we notice that we've crossed into the second > vblank since the flip was queued. I was wondering if we should try to > boost already after the first vblank. But doing that is a bit more > problematic since we process the "flip done" interrupt after the > vblank interrupt. So simply changing the check to >0 would end up > boosting every time even if the flip already happened and we're just > about to complete it when we get to processing the "flip done" > interrupt.
Exactly. It is a little too eager if we start boosting after one missed vblank as we process the vblank before the flip-complete. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
