[Intel-gfx] [PATCH i-g-t] i915/i915_pm_rc6_residency: Make ringbuffer rc6 fast

[Andi Shyti]

Hi Chris,

On Tue, Mar 24, 2020 at 12:52:33PM +0000, Chris Wilson wrote:
> The legacy ringbuffer submission lacks a fast soft-rc6
> mechanism as we have no interrupt for an idle ring. As such
> we are at the mercy of HW RC6... which is not quite as
> precise as we need to pass this test. Oh well.
> 
> Since HW is not fast enough to minimise power draw, tell the driver to
> park as soon as we know we are idle. One day, we hope for the driver to
> discover a mechanism to do this for itself, for as this test shows that
> can save us Watts!
> 
> Closes: https://gitlab.freedesktop.org/drm/intel/issues/1516
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

Reviewed-by: Andi Shyti <andi.shyti at intel.com>

Andi