[Intel-gfx] [PATCH 1/9] drm/i915: Clear fb_tracking.busy_bits also for synchronous flips

[Chris Wilson]

On Thu, Jun 18, 2015 at 11:32:53AM +0300, Ville Syrjälä wrote:
> On Thu, Jun 18, 2015 at 10:30:20AM +0200, Daniel Vetter wrote:
> > The current/old frontbuffer might still have gpu frontbuffer rendering
> > pending. But once flipped it won't have the corresponding frontbuffer
> > bits any more and hence the request retire function won't ever clear
> > the corresponding busy bits. The async flip tracking (with the
> > flip_prepare and flip_complete functions) already does this, but
> > somehow I've forgotten to do this for synchronous flips.
> > 
> > Note that we don't track outstanding rendering of the new framebuffer
> > with busy_bits since all our plane update code waits for previous
> > rendering to complete before displaying a new buffer. Hence a new
> > buffer will never be busy.
> > 
> > Reported-by: Paulo Zanoni <przanoni at gmail.com>
> > Cc: Paulo Zanoni <przanoni at gmail.com>
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > ---
> > Paulo promised to also extend kms_frontbuffer_tracking with flip vs.
> > busy buffer tests.
> > ---
> >  drivers/gpu/drm/i915/intel_drv.h         | 18 ++----------------
> >  drivers/gpu/drm/i915/intel_frontbuffer.c | 26 ++++++++++++++++++++++++++
> >  2 files changed, 28 insertions(+), 16 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index bcafefcf048b..b7c69460fb20 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -963,23 +963,9 @@ void intel_frontbuffer_flip_complete(struct drm_device *dev,
> >  				     unsigned frontbuffer_bits);
> >  void intel_frontbuffer_flush(struct drm_device *dev,
> >  			     unsigned frontbuffer_bits);
> > -/**
> > - * intel_frontbuffer_flip - synchronous frontbuffer flip
> > - * @dev: DRM device
> > - * @frontbuffer_bits: frontbuffer plane tracking bits
> > - *
> > - * This function gets called after scheduling a flip on @obj. This is for
> > - * synchronous plane updates which will happen on the next vblank and which will
> > - * not get delayed by pending gpu rendering.
> > - *
> > - * Can be called without any locks held.
> > - */
> > -static inline
> > +inline
> 
> inline?

Daniel's probably looked at a perf profile and felt guilty. :)

Hijacking the thread purely to promote
http://cgit.freedesktop.org/~ickle/linux-2.6/commit/?h=nightly&id=fe05042a9dda46f4bdd9e40612bf48befaee1ad3
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre