[Intel-gfx] [PATCH 3/4] drm/i915: Disable/Enable PM Intrrupts based on the current freq.

[S, Deepak]

Hi Ville,

On VLV, we  do get the interrupts when we should not. That is when we already in max_delay we get the up threshold interrupts

Thanks
Deepak

-----Original Message-----
From: Ville Syrjälä [mailto:ville.syrjala at linux.intel.com] 
Sent: Monday, December 9, 2013 3:42 PM
To: S, Deepak
Cc: intel-gfx at lists.freedesktop.org
Subject: Re: [Intel-gfx] [PATCH 3/4] drm/i915: Disable/Enable PM Intrrupts based on the current freq.

On Sun, Dec 08, 2013 at 02:16:45PM +0530, deepak.s at intel.com wrote:
> From: Deepak S <deepak.s at intel.com>
> 
> When current delay is already at max delay, Let's disable the PM UP 
> THRESHOLD INTRRUPTS, so that we will not get further interrupts until 
> current delay is less than max delay, Also request for the PM DOWN 
> THRESHOLD INTRRUPTS to indicate the decrease in clock freq. and 
> viceversa for PM DOWN THRESHOLD INTRRUPTS.

Are we actually getting these interrupts when we shouldn't? On non-VLV I think GEN6_RP_INTERRUPT_LIMITS should prevent it, but I don't really know about VLV.

> 
> Signed-off-by: Deepak S <deepak.s at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h |  3 +++  
> drivers/gpu/drm/i915/i915_irq.c | 31 +++++++++++++++++++++++++++++--  
> drivers/gpu/drm/i915/intel_pm.c |  3 +++
>  3 files changed, 35 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h 
> b/drivers/gpu/drm/i915/i915_drv.h index a62ac0c..d52a2db 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -915,6 +915,9 @@ struct intel_gen6_power_mgmt {
>  	u8 rp0_delay;
>  	u8 hw_max;
>  
> +	u8 rp_up_masked;
> +	u8 rp_down_masked;
> +
>  	int last_adj;
>  	enum { LOW_POWER, BETWEEN, HIGH_POWER } power;
>  
> diff --git a/drivers/gpu/drm/i915/i915_irq.c 
> b/drivers/gpu/drm/i915/i915_irq.c index 4bde03a..cd82fdd 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -996,7 +996,20 @@ static void gen6_pm_rps_work(struct work_struct *work)
>  			adj *= 2;
>  		else
>  			adj = 1;
> -		new_delay = dev_priv->rps.cur_delay + adj;
> +
> +		if (dev_priv->rps.cur_delay >= dev_priv->rps.max_delay) {
> +			I915_WRITE(GEN6_PMINTRMSK,
> +					I915_READ(GEN6_PMINTRMSK) | 1 << 5);
> +			dev_priv->rps.rp_up_masked = 1;
> +			new_delay = dev_priv->rps.cur_delay;
> +		} else
> +			new_delay = dev_priv->rps.cur_delay + adj;
> +
> +		if (dev_priv->rps.rp_down_masked) {
> +			I915_WRITE(GEN6_PMINTRMSK,
> +					I915_READ(GEN6_PMINTRMSK) | ~(1 << 4));
> +			dev_priv->rps.rp_down_masked = 0;
> +		}
>  
>  		/*
>  		 * For better performance, jump directly @@ -1015,7 +1028,21 @@ 
> static void gen6_pm_rps_work(struct work_struct *work)
>  			adj *= 2;
>  		else
>  			adj = -1;
> -		new_delay = dev_priv->rps.cur_delay + adj;
> +
> +		if (dev_priv->rps.cur_delay <= dev_priv->rps.max_delay) {
> +			I915_WRITE(GEN6_PMINTRMSK,
> +					I915_READ(GEN6_PMINTRMSK) | 1 << 4);
> +			dev_priv->rps.rp_down_masked = 1;
> +			new_delay = dev_priv->rps.cur_delay;
> +		} else
> +			new_delay = dev_priv->rps.cur_delay + adj;
> +
> +		if (dev_priv->rps.rp_up_masked) {
> +			I915_WRITE(GEN6_PMINTRMSK,
> +					I915_READ(GEN6_PMINTRMSK) | ~(1 << 5));
> +			dev_priv->rps.rp_up_masked = 0;
> +		}
> +
>  	} else { /* unknown event */
>  		new_delay = dev_priv->rps.cur_delay;
>  	}
> diff --git a/drivers/gpu/drm/i915/intel_pm.c 
> b/drivers/gpu/drm/i915/intel_pm.c index 716ca24..6b80ec4 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4186,6 +4186,9 @@ static void valleyview_enable_rps(struct drm_device *dev)
>  			 vlv_gpu_freq(dev_priv, dev_priv->rps.rpe_delay),
>  			 dev_priv->rps.rpe_delay);
>  
> +	dev_priv->rps.rp_up_masked = 0;
> +	dev_priv->rps.rp_down_masked = 0;
> +
>  	valleyview_set_rps(dev_priv->dev, dev_priv->rps.rpe_delay);
>  
>  	gen6_enable_rps_interrupts(dev);
> --
> 1.8.4.2
> 
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--
Ville Syrjälä
Intel OTC