[Intel-gfx] [PATCH 16/19] drm/i915: sanity check power well sw state against hw state

[Imre Deak]

On Tue, 2014-02-18 at 18:55 +0200, Ville Syrjälä wrote:
> On Tue, Feb 18, 2014 at 12:02:17AM +0200, Imre Deak wrote:
> > Suggested by Daniel.
> > 
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_pm.c | 33 ++++++++++++++++++++++++++++++---
> >  1 file changed, 30 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index e81e7de..21ccf89 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -5338,6 +5338,24 @@ static void hsw_power_well_disable(struct drm_i915_private *dev_priv,
> >  	hsw_enable_package_c8(dev_priv);
> >  }
> >  
> > +static void check_power_well_state(struct drm_i915_private *dev_priv,
> > +				   struct i915_power_well *power_well)
> > +{
> > +	bool enabled;
> > +
> > +	if (!power_well->ops->is_enabled)
> > +		return;
> > +
> > +	enabled = power_well->ops->is_enabled(dev_priv, power_well);
> > +
> > +	if (enabled != (power_well->count > 0 || !i915.disable_power_well)) {
> 
> Doesn't i915.disable_power_well==true mean "leave power wells always
> enabled"? So I think the '!' needs to be removed.

No, i915.disable_power_well==true means disable power wells when the
refcount goes to 0. Perhaps not the best name/semantics for this kind of
option, the default for it should be 0 and mean normal operation, which
is to disable power wells when possible.

> > +		DRM_ERROR("state mismatch for '%s' (hw state %d use-count %d disable_power_well %d\n",
> > +			  power_well->name, enabled, power_well->count,
> > +			  i915.disable_power_well);
> > +		WARN_ON(1);
> > +	}
> 
> For an error message + backtrace, you could just use WARN().

Ok.

> > +}
> > +
> >  void intel_display_power_get(struct drm_i915_private *dev_priv,
> >  			     enum intel_display_power_domain domain)
> >  {
> > @@ -5349,9 +5367,14 @@ void intel_display_power_get(struct drm_i915_private *dev_priv,
> >  
> >  	mutex_lock(&power_domains->lock);
> >  
> > -	for_each_power_well(i, power_well, BIT(domain), power_domains)
> > -		if (!power_well->count++ && power_well->ops->enable)
> > +	for_each_power_well(i, power_well, BIT(domain), power_domains) {
> > +		if (!power_well->count++ && power_well->ops->enable) {
> > +			DRM_DEBUG_KMS("enabling %s\n", power_well->name);
> >  			power_well->ops->enable(dev_priv, power_well);
> > +		}
> > +
> > +		check_power_well_state(dev_priv, power_well);
> > +	}
> >  
> >  	power_domains->domain_use_count[domain]++;
> >  
> > @@ -5376,8 +5399,12 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
> >  		WARN_ON(!power_well->count);
> >  
> >  		if (!--power_well->count && power_well->ops->disable &&
> > -		    i915.disable_power_well)
> > +		    i915.disable_power_well) {
> > +			DRM_DEBUG_KMS("disabling %s\n", power_well->name);
> >  			power_well->ops->disable(dev_priv, power_well);
> > +		}
> > +
> > +		check_power_well_state(dev_priv, power_well);
> >  	}
> >  
> >  	mutex_unlock(&power_domains->lock);
> > -- 
> > 1.8.4
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 

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