[Intel-gfx] [PATCH 1/3] drm/i915: Macros to convert PM time interval values to microseconds

[Chris Wilson]

On Tue, Apr 26, 2016 at 04:06:05PM +0200, Daniel Vetter wrote:
> On Sat, Apr 23, 2016 at 12:05:44AM +0530, akash.goel at intel.com wrote:
> > From: Akash Goel <akash.goel at intel.com>
> > 
> > Added a new GT_PM_INTERVAL_TO_US macro to perform the platform
> > specific conversion of PM time interval values to microseconds unit.
> > 
> > Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Signed-off-by: Akash Goel <akash.goel at intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 9464ba3..eacd9ae 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -2939,6 +2939,15 @@ enum skl_disp_power_wells {
> >  				INTERVAL_1_33_US(us)) : \
> >  				INTERVAL_1_28_US(us))
> >  
> > +#define INTERVAL_1_28_TO_US(interval)  (((interval) << 7) / 100)
> > +#define INTERVAL_1_33_TO_US(interval)  (((interval) << 2) / 3)
> > +#define INTERVAL_0_833_TO_US(interval) (((interval) * 5)  / 6)
> > +#define GT_PM_INTERVAL_TO_US(dev_priv, interval) (IS_GEN9(dev_priv) ? \
> > +                           (IS_BROXTON(dev_priv) ? \
> > +                           INTERVAL_0_833_TO_US(interval) : \
> > +                           INTERVAL_1_33_TO_US(interval)) : \
> > +                           INTERVAL_1_28_TO_US(interval))
> 
> Bikeshed, but I think once we have platform logic in there a real inline
> functino starts to look better.

Or when we have many, a feature flag. Could be worse, each could be
expanding to devid.
> 
> Feel free to ignore since already pushed.

Yeah, since this was cut'n'paste for debugfs, I wasn't that concerned
about elegance just that I could compare the macros and check that it
was the inverse.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre