[Intel-gfx] [PATCH 22/21] drm/i915: Assert the dbuf is enabled when disabling DC5/6

[Ville Syrjälä]

On Thu, May 19, 2016 at 10:49:23PM +0300, Imre Deak wrote:
> On Mon, 2016-05-16 at 16:59 +0300, ville.syrjala at linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > Like with cdclk, the DMC is supposed to manage dbuf enabling/disabling.
> > Let's make sure it has correctly restored the dbuf state to enabled
> > when we disable the DC states.
> > 
> > Cc: Imre Deak <imre.deak at intel.com>
> > Suggested-by: Imre Deak <imre.deak at intel.com>
> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_runtime_pm.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index b70e123f67ca..27cb92c18bb5 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -806,6 +806,15 @@ static bool gen9_dc_off_power_well_enabled(struct drm_i915_private *dev_priv,
> >  	return (I915_READ(DC_STATE_EN) & DC_STATE_EN_UPTO_DC5_DC6_MASK) == 0;
> >  }
> >  
> > +static void skl_assert_dbuf_enabled(struct drm_i915_private *dev_priv)
> 
> I would've used gen9_ prefix. Either way:

Changed while applying.

> Reviewed-by: Imre Deak <imre.deak at intel.com>
> 
> > +{
> > +	u32 tmp = I915_READ(DBUF_CTL);
> > +
> > +	WARN((tmp & (DBUF_POWER_STATE | DBUF_POWER_REQUEST)) !=
> > +	     (DBUF_POWER_STATE | DBUF_POWER_REQUEST),
> > +	     "Unexpected DBuf power power state (0x%08x)\n", tmp);
> > +}
> > +
> >  static void gen9_dc_off_power_well_enable(struct drm_i915_private *dev_priv,
> >  					  struct i915_power_well *power_well)
> >  {
> > @@ -814,6 +823,8 @@ static void gen9_dc_off_power_well_enable(struct drm_i915_private *dev_priv,
> >  	WARN_ON(dev_priv->cdclk_freq !=
> >  		dev_priv->display.get_display_clock_speed(dev_priv->dev));
> >  
> > +	skl_assert_dbuf_enabled(dev_priv);
> > +
> >  	if (IS_BROXTON(dev_priv))
> >  		broxton_ddi_phy_verify_state(dev_priv);
> >  }

-- 
Ville Syrjälä
Intel OTC