Re: [PATCH 11/35] drm/i915: Add SNB/IVB support to intel_read_wm_latency

[Daniel Vetter <daniel@ffwll.ch>]

On Tue, Jul 30, 2013 at 06:01:57PM -0300, Paulo Zanoni wrote:
> 2013/7/5  <ville.syrjala@linux.intel.com>:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > SNB and IVB have slightly a different way to read out the
> > watermark latency values.
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_pm.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index a2ca018..6ff89c6 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -2350,6 +2350,13 @@ static void intel_read_wm_latency(struct drm_device *dev, uint16_t wm[5])
> >                 wm[2] = (sskpd >> 12) & 0xFF;
> >                 wm[3] = (sskpd >> 20) & 0x1FF;
> >                 wm[4] = (sskpd >> 32) & 0x1FF;
> > +       } else if (INTEL_INFO(dev)->gen >= 6) {
> > +               uint32_t sskpd = I915_READ(MCH_SSKPD);
> > +
> > +               wm[0] = (sskpd >> SSKPD_WM0_SHIFT) & SSKPD_WM_MASK;
> > +               wm[1] = (sskpd >> SSKPD_WM1_SHIFT) & SSKPD_WM_MASK;
> > +               wm[2] = (sskpd >> SSKPD_WM2_SHIFT) & SSKPD_WM_MASK;
> > +               wm[3] = (sskpd >> SSKPD_WM3_SHIFT) & SSKPD_WM_MASK;
> 
> My documentation is limited, but this seems at least consistent with
> our current definitions.
> 
> I'd also vote to transform this into a "switch (INTEL_INFO(dev))" and
> add a WARN in case Gen is not 6 or 7.

I guess we can do that once all the stuff here (and maybe 1-2 new
generations) have landed.
> 
> Anyway, the patch looks correct: Reviewed-by: Paulo Zanoni
> <paulo.r.zanoni@intel.com>

Ok, I've pulled in all the patches Paulo has already reviewed and deemed
good. I guess to continue we need to dig out the ilk docs for Paulo ;-)

Thanks for the patches&review.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch