Re: [PATCH v3 1/3] drm/i915: Disable/Enable PM Intrrupts based on the current freq.

[Daniel Vetter <daniel@ffwll.ch>]

On Thu, Jan 09, 2014 at 07:31:08PM +0530, deepak.s@intel.com wrote:
> From: Deepak S <deepak.s@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.
> 
> v2: Use bool variables (Daniel)
> 
> v3: Fix Interrupt masking bit (Deepak)
> 
> Signed-off-by: Deepak S <deepak.s@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 cc8afff..d49e674 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -943,6 +943,9 @@ struct intel_gen6_power_mgmt {
>  	u8 rp0_delay;
>  	u8 hw_max;
>  
> +	bool rp_up_masked;
> +	bool 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 1d44c79..e87d47a 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -988,7 +988,20 @@ 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);

Please use the symbolic constants in i915_reg.h, we can reuse the ones
below GEN6_PMIER. Also Chris had some comment to move this code around,
but I didn't really understand what he wants. Chris, can you please
clarify?

Thanks, Daniel

> +			dev_priv->rps.rp_up_masked = true;
> +			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 = false;
> +		}
>  
>  		/*
>  		 * For better performance, jump directly
> @@ -1007,7 +1020,21 @@ 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.min_delay) {
> +			I915_WRITE(GEN6_PMINTRMSK,
> +					I915_READ(GEN6_PMINTRMSK) | 1 << 4);
> +			dev_priv->rps.rp_down_masked = true;
> +			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 = false;
> +		}
> +
>  	} 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 469170c..9c950e4 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3628,6 +3628,9 @@ 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 = false;
> +	dev_priv->rps.rp_down_masked = false;
> +
>  	valleyview_set_rps(dev_priv->dev, dev_priv->rps.rpe_delay);
>  
>  	gen6_enable_rps_interrupts(dev);
> -- 
> 1.8.4.2
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch