[Intel-gfx] [RFC][PATCH 1/2] drm/i915: Don't increase the GPU frequency from the delayed VLV rps timer

[Jesse Barnes]

On Tue, 25 Jun 2013 21:38:10 +0300
ville.syrjala at linux.intel.com wrote:

> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> There's little point in increasing the GPU frequency from the delayed
> rps work on VLV. Now when the GPU is idle, the GPU frequency actually
> keeps dropping gradually until it hits the minimum, whereas previously
> it just ping-ponged constantly between RPe and RPe-1.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_pm.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 96cfb3e..eaf0fa2 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3464,7 +3464,8 @@ static void vlv_rps_timer_work(struct work_struct *work)
>  	 * min freq available.
>  	 */
>  	mutex_lock(&dev_priv->rps.hw_lock);
> -	valleyview_set_rps(dev_priv->dev, dev_priv->rps.rpe_delay);
> +	if (dev_priv->rps.cur_delay > dev_priv->rps.rpe_delay)
> +		valleyview_set_rps(dev_priv->dev, dev_priv->rps.rpe_delay);
>  	mutex_unlock(&dev_priv->rps.hw_lock);
>  }
>  

Hm that's not what I saw here; I stopped getting the timer interrupts
when the GPU went idle.  But that could be explained by punit fw
differences.

So this change looks ok to me.

Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center