Re: [PATCH 6/7] drm/i915/chv: Added CHV specific DDR fetch into init_clock_gating

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, May 27, 2014 at 01:42:50PM +0200, Daniel Vetter wrote:
> On Mon, May 26, 2014 at 06:19:07PM +0300, Mika Kuoppala wrote:
> > deepak.s@linux.intel.com writes:
> > 
> > > From: Deepak S <deepak.s@linux.intel.com>
> > >
> > > Signed-off-by: Deepak S <deepak.s@linux.intel.com>
> > > [vsyrjala: Fix merge fubmle where the code ended up in
> > > g4x_disable_trickle_feed() instead of cherryview_init_clock_gating()]
> > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > Acked-by: Ben Widawsky <ben@bwidawsk.net>
> > > ---
> > >  drivers/gpu/drm/i915/intel_pm.c | 11 +++++++++++
> > >  1 file changed, 11 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > > index 08dcdc5..0b73a6d 100644
> > > --- a/drivers/gpu/drm/i915/intel_pm.c
> > > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > > @@ -4026,7 +4026,18 @@ static void cherryview_enable_rps(struct drm_device *dev)
> > >  		   GEN6_RP_UP_BUSY_AVG |
> > >  		   GEN6_RP_DOWN_IDLE_AVG);
> > >  
> > > +	/* ToDo: Update the mem freq based on latest spec [CHV]*/
> > 
> > Please do and consider fixing the vlv decoding. It seems to be off
> > too.
> 
> Poke about this one here. Iirc the situation on vlv is simply terminal
> confusion, and iirc the current code matches reality of shipping vbiosen,
> but not any spec.

Yeah changed back here:

commit f6d519481b662d9fc52836e6e6107520f03e0122
Author: Deepak S <deepak.s@linux.intel.com>
Date:   Thu Apr 3 21:01:28 2014 +0530

    Revert "drm/i915/vlv: fixup DDR freq detection per Punit spec"
    
    As per the inputs provided by hardware team  we still use DDR
    Rates as 0,1=800, 2=1066, 3=1333.
    With this change, Turbo freqs used on current machines matches.


I think what we need is a comment there which states why
we're going against the spec, just to avoid future confusion
and someone accidentally changing it back again.

> I hope we're bettter for chv.

One can dream.

-- 
Ville Syrjälä
Intel OTC