[Intel-gfx] [PATCH v4] drm/i915: use hrtimer in wait for vblank

[Chris Wilson]

On Tue, Mar 25, 2014 at 02:28:22PM +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.
> 
> As per kernel document "Documentation/timers/timers-howto.txt" sleeping
> for 10us to 20ms its recomended to use usleep_range.
> 
> Signed-off-by: Arun R Murthy <arun.r.murthy at intel.com>

Lgtm, I still feel that our use of W=1 is fairly arbitrary and worth
tweaking in future.

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre