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

[Murthy, Arun R]

On Tuesday 25 March 2014 01:00 PM, Chris Wilson wrote:
> 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

Will revert this additional wait_for_X.
Will update the existing _wait_for as per the kernel documentation for 
timers.

Thanks and Regards,
Arun R Murthy
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