[Intel-gfx] [PATCH v3] drm/i915: use hrtimer in wait for vblank

[Chris Wilson]

On Tue, Mar 25, 2014 at 11:29:02AM +0530, Arun R Murthy wrote:
> In wait for vblank use usleep_range, which will use hrtimers instead of
> msleep. Using msleep(1~20) there are more chances of sleeping for 20ms.
> Using usleep_range uses hrtimers and hence are precise, worst case will
> trigger an interrupt at the higher/max timeout.
> 
> Change-log: On replacing msleep(1) with usleep_range(1000, 2000) we have
> noticed the time consumed by wait for vblank is ~4ms to ~17ms.
> 
> Change-Id: I6672e5697b01987a6d069ab06e76d97287b1f7ae
> Signed-off-by: Arun R Murthy <arun.r.murthy at intel.com>

No. I feel strongly that we do not want more wait_for_X() with strange
semantics.
http://sweng.the-davies.net/Home/rustys-api-design-manifesto
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre