[Intel-gfx] [PATCH] drm/i915: Boost GPU clocks if we miss the pageflip's vblank

[Szwichtenberg, Radoslaw]

On Fri, 2017-08-18 at 08:54 +0100, Chris Wilson wrote:
> Quoting Chris Wilson (2017-08-17 13:37:06)
> > If we miss the current vblank because the gpu was busy, that may cause a
> > jitter as the frame rate temporarily drops. We try to limit the impact
> > of this by then boosting the GPU clock to deliver the frame as quickly
> > as possible. Originally done in commit 6ad790c0f5ac ("drm/i915: Boost GPU
> > frequency if we detect outstanding pageflips") but was never forward
> > ported to atomic and finally dropped in commit fd3a40242e87 ("drm/i915:
> > Rip out legacy page_flip completion/irq handling").
> 
>  
> > References: https://bugs.freedesktop.org/show_bug.cgi?id=102199
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102199
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Daniel Vetter <daniel.vetter at intel.com>
> 
> Tested-by: Lyude Paul <lyude at redhat.com>
Reviewed-by: Radoslaw Szwichtenberg <radoslaw.szwichtenberg at intel.com>