[Intel-gfx] [PATCH] drm/i915: Only unmask required PM interrupts

[Daniel Vetter]

On Wed, Aug 14, 2013 at 10:34 PM, Vinit Azad <vinit.azad at intel.com> wrote:
> Un-masking all PM interrupts causes hardware to generate
> interrupts regardless of whether the interrupts are enabled
> on the DE side. Since turbo only need up/down threshold and
> rc6 timeout interrupt, mask all other interrupts bits to avoid
> unnecessary overhead/wake up.

Just to clarify since I can't really believe this yet: Even though we
disable all other interrupt sources in PMIER and mask them in PMIMR hw
still manages to fire off our interrupt handler? Do those interrupts
end up setting PMIIR?

Thanks, Daniel
>
> Change-Id: I6c947df6fd5f60584d39b9e8b8c89faa51a5e827
> Signed-off-by: Vinit Azad <vinit.azad at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_pm.c |    8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 8e9ce07..17a0dae 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3328,8 +3328,8 @@ static void gen6_enable_rps(struct drm_device *dev)
>         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->rps.lock);
> -       /* unmask all PM interrupts */
> -       I915_WRITE(GEN6_PMINTRMSK, 0);
> +       /* only unmask PM interrupts we need. Mask all others. */
> +       I915_WRITE(GEN6_PMINTRMSK, ~GEN6_PM_RPS_EVENTS);
>
>         rc6vids = 0;
>         ret = sandybridge_pcode_read(dev_priv, GEN6_PCODE_READ_RC6VIDS, &rc6vids);
> @@ -3596,8 +3596,8 @@ static void valleyview_enable_rps(struct drm_device *dev)
>         WARN_ON(dev_priv->rps.pm_iir != 0);
>         I915_WRITE(GEN6_PMIMR, 0);
>         spin_unlock_irq(&dev_priv->rps.lock);
> -       /* enable all PM interrupts */
> -       I915_WRITE(GEN6_PMINTRMSK, 0);
> +       /* enable only the PM interrupts we need. Mask everything else */
> +       I915_WRITE(GEN6_PMINTRMSK, ~GEN6_PM_RPS_EVENTS);
>
>         gen6_gt_force_wake_put(dev_priv);
>  }
> --
> 1.7.9.5
>
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch