Re: [PATCH 14/28] drm/i915: disable watermarks on VLV, pondicherry takes care of this

From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 14/28] drm/i915: disable watermarks on VLV, pondicherry takes care of this
Date: Wed, 6 Mar 2013 21:09:06 +0200	[thread overview]
Message-ID: <20130306190906.GL4469@intel.com> (raw)
In-Reply-To: <20130306185633.GS9021@phenom.ffwll.local>

On Wed, Mar 06, 2013 at 07:56:33PM +0100, Daniel Vetter wrote:
> On Fri, Mar 01, 2013 at 01:14:17PM -0800, Jesse Barnes wrote:
> > For current usage, not needed.
> > 
> > Signed-off-by: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_pm.c |    4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index 7de8cec..b8f5a17 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -4211,7 +4211,9 @@ void intel_init_pm(struct drm_device *dev)
> >  		} else
> >  			dev_priv->display.update_wm = NULL;
> >  	} else if (IS_VALLEYVIEW(dev)) {
> > -		dev_priv->display.update_wm = valleyview_update_wm;
> > +//		dev_priv->display.update_wm = valleyview_update_wm;
> > +		dev_priv->display.update_wm = NULL;
> > +//		dev_priv->display.update_sprite_wm = valleyview_update_sprite_wm;
> 
> Either kill this all (it's kzalloced so no need for NULL assignments) or
> add a giant comment explaining what's going on. Adding commented-out code
> without comment is strange ...

The whole premise that pondicherry magically handles things is a bit
weird too. I suppose all it really means is that the default WMs were
high enough to avoid underruns for the guys who tested this.

Actually wasn't there a comment on an earlier version of this patch
that there was a div by zero or something, and that's the real reason
for this patch?

> -Daniel
> 
> >  		dev_priv->display.init_clock_gating =
> >  			valleyview_init_clock_gating;
> >  	} else if (IS_PINEVIEW(dev)) {
> > -- 
> > 1.7.9.5
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel OTC