[Intel-gfx] [PATCH 3/3] drm/i915: Mask PM interrupt generation when at up/down limits

[Chris Wilson]

On Thu, Mar 27, 2014 at 08:24:21AM +0000, Chris Wilson wrote:
> The speculation is that we can conserve more power by masking off the
> interrupts at source (PMINTRMSK) rather than filtering them by the
> up/down thresholds (RPINTLIM).
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Deepak S <deepak.s at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_pm.c | 32 ++++++++++++++++++++------------
>  1 file changed, 20 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 3ad590924062..0a76e9baeca2 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3006,6 +3006,25 @@ static void gen6_set_rps_thresholds(struct drm_i915_private *dev_priv, u8 val)
>  	dev_priv->rps.last_adj = 0;
>  }
>  
> +static u32 gen6_rps_pm_mask(struct drm_i915_private *dev_priv, u8 val)
> +{
> +	u32 mask;
> +
> +	mask = GEN6_PM_RP_DOWN_TIMEOUT;
> +	if (val > dev_priv->rps.min_freq_softlimit)
> +		mask |= GEN6_PM_RP_DOWN_THRESHOLD;

Actually we only need DOWN_TIMEOUT when above min freq as well.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre