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

[Chris Wilson]

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>
-Chris