Re: [PATCH 13/14] drm/i915: extract rps interrupt enable/disable helpers

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, Jul 10, 2013 at 06:12:13PM -0300, Paulo Zanoni wrote:
> 2013/7/4 Daniel Vetter <daniel.vetter@ffwll.ch>:
> > This just unifies the vlv code with the snb-hsw code which matched
> > exactly before the VECS enabling.
> 
> So now the VLV code is behaving differently. Is that intentional? You
> could write about the implications here.

It's just for consistency that we now also reset GEN6_PMINTRMSK for vlv
and that the additional clearing of the rps event bits in PMIIR now
consistently happens in enable_interrupts. Like I've said in the next
commit message, the PMIIR handling here still smells a bit funny - as long
as we properly clear them at irq install time and keep the actual rps
events masked we should never see PMIIR bits here.
-Daniel

> 
> 
> >
> > Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > ---
> >  drivers/gpu/drm/i915/intel_pm.c | 59 ++++++++++++++++++++---------------------
> >  1 file changed, 29 insertions(+), 30 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> > index 96f0872..787a528 100644
> > --- a/drivers/gpu/drm/i915/intel_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_pm.c
> > @@ -3121,13 +3121,10 @@ void valleyview_set_rps(struct drm_device *dev, u8 val)
> >         trace_intel_gpu_freq_change(vlv_gpu_freq(dev_priv->mem_freq, val));
> >  }
> >
> > -
> > -static void gen6_disable_rps(struct drm_device *dev)
> > +static void gen6_disable_rps_interrupts(struct drm_device *dev)
> >  {
> >         struct drm_i915_private *dev_priv = dev->dev_private;
> >
> > -       I915_WRITE(GEN6_RC_CONTROL, 0);
> > -       I915_WRITE(GEN6_RPNSWREQ, 1 << 31);
> >         I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);
> >         I915_WRITE(GEN6_PMIER, I915_READ(GEN6_PMIER) & ~GEN6_PM_RPS_EVENTS);
> >         /* Complete PM interrupt masking here doesn't race with the rps work
> > @@ -3142,23 +3139,23 @@ static void gen6_disable_rps(struct drm_device *dev)
> >         I915_WRITE(GEN6_PMIIR, GEN6_PM_RPS_EVENTS);
> >  }
> >
> > -static void valleyview_disable_rps(struct drm_device *dev)
> > +static void gen6_disable_rps(struct drm_device *dev)
> >  {
> >         struct drm_i915_private *dev_priv = dev->dev_private;
> >
> >         I915_WRITE(GEN6_RC_CONTROL, 0);
> > -       I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);
> > -       I915_WRITE(GEN6_PMIER, 0);
> > -       /* Complete PM interrupt masking here doesn't race with the rps work
> > -        * item again unmasking PM interrupts because that is using a different
> > -        * register (PMIMR) to mask PM interrupts. The only risk is in leaving
> > -        * stale bits in PMIIR and PMIMR which gen6_enable_rps will clean up. */
> > +       I915_WRITE(GEN6_RPNSWREQ, 1 << 31);
> >
> > -       spin_lock_irq(&dev_priv->irq_lock);
> > -       dev_priv->rps.pm_iir = 0;
> > -       spin_unlock_irq(&dev_priv->irq_lock);
> > +       gen6_disable_rps_interrupts(dev);
> > +}
> > +
> > +static void valleyview_disable_rps(struct drm_device *dev)
> > +{
> > +       struct drm_i915_private *dev_priv = dev->dev_private;
> > +
> > +       I915_WRITE(GEN6_RC_CONTROL, 0);
> >
> > -       I915_WRITE(GEN6_PMIIR, I915_READ(GEN6_PMIIR));
> > +       gen6_disable_rps_interrupts(dev);
> >
> >         if (dev_priv->vlv_pctx) {
> >                 drm_gem_object_unreference(&dev_priv->vlv_pctx->base);
> > @@ -3191,6 +3188,21 @@ int intel_enable_rc6(const struct drm_device *dev)
> >         return (INTEL_RC6_ENABLE | INTEL_RC6p_ENABLE);
> >  }
> >
> > +static void gen6_enable_rps_interrupts(struct drm_device *dev)
> > +{
> > +       struct drm_i915_private *dev_priv = dev->dev_private;
> > +
> > +       spin_lock_irq(&dev_priv->irq_lock);
> > +       /* FIXME: Our interrupt enabling sequence is bonghits.
> > +        * dev_priv->rps.pm_iir really should be 0 here. */
> > +       dev_priv->rps.pm_iir = 0;
> > +       I915_WRITE(GEN6_PMIMR, I915_READ(GEN6_PMIMR) & ~GEN6_PM_RPS_EVENTS);
> > +       I915_WRITE(GEN6_PMIIR, GEN6_PM_RPS_EVENTS);
> > +       spin_unlock_irq(&dev_priv->irq_lock);
> > +       /* unmask all PM interrupts */
> > +       I915_WRITE(GEN6_PMINTRMSK, 0);
> > +}
> > +
> >  static void gen6_enable_rps(struct drm_device *dev)
> >  {
> >         struct drm_i915_private *dev_priv = dev->dev_private;
> > @@ -3319,15 +3331,7 @@ static void gen6_enable_rps(struct drm_device *dev)
> >
> >         gen6_set_rps(dev_priv->dev, (gt_perf_status & 0xff00) >> 8);
> >
> > -       spin_lock_irq(&dev_priv->irq_lock);
> > -       /* FIXME: Our interrupt enabling sequence is bonghits.
> > -        * dev_priv->rps.pm_iir really should be 0 here. */
> > -       dev_priv->rps.pm_iir = 0;
> > -       I915_WRITE(GEN6_PMIMR, I915_READ(GEN6_PMIMR) & ~GEN6_PM_RPS_EVENTS);
> > -       I915_WRITE(GEN6_PMIIR, GEN6_PM_RPS_EVENTS);
> > -       spin_unlock_irq(&dev_priv->irq_lock);
> > -       /* unmask all PM interrupts */
> > -       I915_WRITE(GEN6_PMINTRMSK, 0);
> > +       gen6_enable_rps_interrupts(dev);
> >
> >         rc6vids = 0;
> >         ret = sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
> > @@ -3597,12 +3601,7 @@ static void valleyview_enable_rps(struct drm_device *dev)
> >
> >         valleyview_set_rps(dev_priv->dev, dev_priv->rps.rpe_delay);
> >
> > -       spin_lock_irq(&dev_priv->irq_lock);
> > -       WARN_ON(dev_priv->rps.pm_iir != 0);
> > -       I915_WRITE(GEN6_PMIMR, 0);
> > -       spin_unlock_irq(&dev_priv->irq_lock);
> > -       /* enable all PM interrupts */
> > -       I915_WRITE(GEN6_PMINTRMSK, 0);
> > +       gen6_enable_rps_interrupts(dev);
> >
> >         gen6_gt_force_wake_put(dev_priv);
> >  }
> > --
> > 1.8.1.4
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> 
> 
> -- 
> Paulo Zanoni

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