Re: [PATCH v2 3/5] drm/i915/skl: Restructured the gen6_set_rps_thresholds function

[Damien Lespiau <damien.lespiau@intel.com>]

On Wed, Feb 18, 2015 at 07:31:15PM +0530, akash.goel@intel.com wrote:
> From: Akash Goel <akash.goel@intel.com>
> 
> Prior to SKL, the time period programmed in Up/Down EI & Up/Down
> threshold registers was in units of 1.28 micro seconds. But for
> SKL, the units have changed (1.333 micro seconds).
> Have generalized the implementation of gen6_set_rps_thresholds function,
> by removing the hard coding done in it as per 1.28 micro seconds.
> 
> v2: Renamed the local variables & removed superfluous comments (Chris)
> 
> Signed-off-by: Akash Goel <akash.goel@intel.com>

Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>

> ---
>  drivers/gpu/drm/i915/intel_pm.c | 68 +++++++++++++++++++----------------------
>  1 file changed, 32 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 1df3fbd..78b4d62 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3643,6 +3643,8 @@ static u32 gen6_rps_limits(struct drm_i915_private *dev_priv, u8 val)
>  static void gen6_set_rps_thresholds(struct drm_i915_private *dev_priv, u8 val)
>  {
>  	int new_power;
> +	u32 threshold_up = 0, threshold_down = 0; /* in % */
> +	u32 ei_up = 0, ei_down = 0;
>  
>  	new_power = dev_priv->rps.power;
>  	switch (dev_priv->rps.power) {
> @@ -3675,59 +3677,53 @@ static void gen6_set_rps_thresholds(struct drm_i915_private *dev_priv, u8 val)
>  	switch (new_power) {
>  	case LOW_POWER:
>  		/* Upclock if more than 95% busy over 16ms */
> -		I915_WRITE(GEN6_RP_UP_EI, 12500);
> -		I915_WRITE(GEN6_RP_UP_THRESHOLD, 11800);
> +		ei_up = 16000;
> +		threshold_up = 95;
>  
>  		/* Downclock if less than 85% busy over 32ms */
> -		I915_WRITE(GEN6_RP_DOWN_EI, 25000);
> -		I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 21250);
> -
> -		I915_WRITE(GEN6_RP_CONTROL,
> -			   GEN6_RP_MEDIA_TURBO |
> -			   GEN6_RP_MEDIA_HW_NORMAL_MODE |
> -			   GEN6_RP_MEDIA_IS_GFX |
> -			   GEN6_RP_ENABLE |
> -			   GEN6_RP_UP_BUSY_AVG |
> -			   GEN6_RP_DOWN_IDLE_AVG);
> +		ei_down = 32000;
> +		threshold_down = 85;
>  		break;
>  
>  	case BETWEEN:
>  		/* Upclock if more than 90% busy over 13ms */
> -		I915_WRITE(GEN6_RP_UP_EI, 10250);
> -		I915_WRITE(GEN6_RP_UP_THRESHOLD, 9225);
> +		ei_up = 13000;
> +		threshold_up = 90;
>  
>  		/* Downclock if less than 75% busy over 32ms */
> -		I915_WRITE(GEN6_RP_DOWN_EI, 25000);
> -		I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 18750);
> -
> -		I915_WRITE(GEN6_RP_CONTROL,
> -			   GEN6_RP_MEDIA_TURBO |
> -			   GEN6_RP_MEDIA_HW_NORMAL_MODE |
> -			   GEN6_RP_MEDIA_IS_GFX |
> -			   GEN6_RP_ENABLE |
> -			   GEN6_RP_UP_BUSY_AVG |
> -			   GEN6_RP_DOWN_IDLE_AVG);
> +		ei_down = 32000;
> +		threshold_down = 75;
>  		break;
>  
>  	case HIGH_POWER:
>  		/* Upclock if more than 85% busy over 10ms */
> -		I915_WRITE(GEN6_RP_UP_EI, 8000);
> -		I915_WRITE(GEN6_RP_UP_THRESHOLD, 6800);
> +		ei_up = 10000;
> +		threshold_up = 85;
>  
>  		/* Downclock if less than 60% busy over 32ms */
> -		I915_WRITE(GEN6_RP_DOWN_EI, 25000);
> -		I915_WRITE(GEN6_RP_DOWN_THRESHOLD, 15000);
> -
> -		I915_WRITE(GEN6_RP_CONTROL,
> -			   GEN6_RP_MEDIA_TURBO |
> -			   GEN6_RP_MEDIA_HW_NORMAL_MODE |
> -			   GEN6_RP_MEDIA_IS_GFX |
> -			   GEN6_RP_ENABLE |
> -			   GEN6_RP_UP_BUSY_AVG |
> -			   GEN6_RP_DOWN_IDLE_AVG);
> +		ei_down = 32000;
> +		threshold_down = 60;
>  		break;
>  	}
>  
> +	I915_WRITE(GEN6_RP_UP_EI,
> +		GT_INTERVAL_FROM_US(ei_up));
> +	I915_WRITE(GEN6_RP_UP_THRESHOLD,
> +		GT_INTERVAL_FROM_US((ei_up * threshold_up / 100)));
> +
> +	I915_WRITE(GEN6_RP_DOWN_EI,
> +		GT_INTERVAL_FROM_US(ei_down));
> +	I915_WRITE(GEN6_RP_DOWN_THRESHOLD,
> +		GT_INTERVAL_FROM_US((ei_down * threshold_down / 100)));
> +
> +	 I915_WRITE(GEN6_RP_CONTROL,
> +		    GEN6_RP_MEDIA_TURBO |
> +		    GEN6_RP_MEDIA_HW_NORMAL_MODE |
> +		    GEN6_RP_MEDIA_IS_GFX |
> +		    GEN6_RP_ENABLE |
> +		    GEN6_RP_UP_BUSY_AVG |
> +		    GEN6_RP_DOWN_IDLE_AVG);
> +
>  	dev_priv->rps.power = new_power;
>  	dev_priv->rps.last_adj = 0;
>  }
> -- 
> 1.9.2
> 
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