[Intel-gfx] [PATCH v4 25/26] drm/i915: Add sysfs interface to know the HW requested frequency

[Chris Wilson]

On Thu, Sep 15, 2016 at 04:14:22PM +0530, Kamble, Sagar A wrote:
> 
> 
> On 9/9/2016 10:13 PM, Chris Wilson wrote:
> >On Fri, Sep 09, 2016 at 06:21:44PM +0530, Sagar Arun Kamble wrote:
> >>With SLPC, user can read this value to know SLPC requested frequency.
> >Not SLPC specific, even elsewhere there may be a delay between the cur
> >value and the req (just means something more on SLPC).
> cur_freq is updated whenever RPNSWREQ is written so they should be
> same right?
> Where will delay come into picture?

RPNSWEQ is only updated from an irq worker. Plenty of scope for
breakage.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre