Re: [PATCH] drm/i915: Only request PM interrupts for the events we handled

[Ben Widawsky <ben@bwidawsk.net>]

On Thu,  5 Jul 2012 15:02:17 +0100
Chris Wilson <chris@chris-wilson.co.uk> wrote:

> There is little point waking up every 10ms to service an interrupt which
> we then promptly ignore. So only program the the PMIER to enable
> interrupts for those events which we do handle, not all of them!
> 
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
> Cc: Eugeni Dodonov <eugeni.dodonov@intel.com>
> Cc: Ben Widawsky <ben@bwidawsk.net>

Agreed, although some of these events do sound interesting.
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>

> ---
>  drivers/gpu/drm/i915/intel_pm.c |    9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 0e27e95..53df531 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -2491,14 +2491,7 @@ static void gen6_enable_rps(struct drm_device *dev)
>  	gen6_set_rps(dev_priv->dev, (gt_perf_status & 0xff00) >> 8);
>  
>  	/* requires MSI enabled */
> -	I915_WRITE(GEN6_PMIER,
> -		   GEN6_PM_MBOX_EVENT |
> -		   GEN6_PM_THERMAL_EVENT |
> -		   GEN6_PM_RP_DOWN_TIMEOUT |
> -		   GEN6_PM_RP_UP_THRESHOLD |
> -		   GEN6_PM_RP_DOWN_THRESHOLD |
> -		   GEN6_PM_RP_UP_EI_EXPIRED |
> -		   GEN6_PM_RP_DOWN_EI_EXPIRED);
> +	I915_WRITE(GEN6_PMIER, GEN6_PM_DEFERRED_EVENTS);
>  	spin_lock_irq(&dev_priv->rps_lock);
>  	WARN_ON(dev_priv->pm_iir != 0);
>  	I915_WRITE(GEN6_PMIMR, 0);



-- 
Ben Widawsky, Intel Open Source Technology Center