[Intel-gfx] [PATCH v5] drm/i915/vlv: WA for Turbo and RC6 to work together.

Ville Syrjälä ville.syrjala at linux.intel.com
Fri Mar 28 13:53:48 CET 2014


On Thu, Mar 27, 2014 at 12:05:01PM +0530, deepak.s at linux.intel.com wrote:
> From: Deepak S <deepak.s at linux.intel.com>
> 
> With RC6 enabled, BYT has an HW issue in determining the right
> Gfx busyness.
> WA for Turbo + RC6: Use SW based Gfx busy-ness detection to decide
> on increasing/decreasing the freq. This logic will monitor C0
> counters of render/media power-wells over EI period and takes
> necessary action based on these values
> 
> v2: Refactor duplicate code. (Ville)
> 
> v3: Reformat the comments. (Ville)
> 
> v4: Enable required counters and remove unwanted code (Ville)
> 
> v5: Resolved comments and remove kernel-doc style comments. (Ville)

That doesn't tell me that you added the frequency change acceleration
support.

> 
> Signed-off-by: Deepak S <deepak.s at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h |  15 +++++
>  drivers/gpu/drm/i915/i915_irq.c | 135 +++++++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/i915_reg.h |  12 +++-
>  drivers/gpu/drm/i915/intel_pm.c |  13 +++-
>  4 files changed, 170 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 7c212f3..c48ea93 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -816,6 +816,12 @@ struct i915_suspend_saved_registers {
>  	u32 savePCH_PORT_HOTPLUG;
>  };
>  
> +struct intel_rps_ei_calc {
> +	u32 cz_ts_ei;
> +	u32 render_ei_c0;
> +	u32 media_ei_c0;
> +};
> +
>  struct intel_gen6_power_mgmt {
>  	/* work and pm_iir are protected by dev_priv->irq_lock */
>  	struct work_struct work;
> @@ -843,6 +849,8 @@ struct intel_gen6_power_mgmt {
>  	bool rp_up_masked;
>  	bool rp_down_masked;
>  
> +	u32 ei_interrupt_count;
> +
>  	int last_adj;
>  	enum { LOW_POWER, BETWEEN, HIGH_POWER } power;
>  
> @@ -1403,6 +1411,13 @@ typedef struct drm_i915_private {
>  	/* gen6+ rps state */
>  	struct intel_gen6_power_mgmt rps;
>  
> +	/* rps wa up ei calculation */
> +	struct intel_rps_ei_calc rps_up_ei;
> +
> +	/* rps wa down ei calculation */
> +	struct intel_rps_ei_calc rps_down_ei;
> +
> +
>  	/* ilk-only ips/rps state. Everything in here is protected by the global
>  	 * mchdev_lock in intel_pm.c */
>  	struct intel_ilk_power_mgmt ips;
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 300f127..4b421b4 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -1121,6 +1121,132 @@ void gen6_set_pm_mask(struct drm_i915_private *dev_priv,
>  	}
>  }
>  
> +static u32 vlv_c0_residency(struct drm_i915_private *dev_priv,
> +				struct  intel_rps_ei_calc *rps_ei)
> +{
> +	u32 cz_ts, cz_freq_khz;
> +	u32 render_count, media_count;
> +	u32 elapsed_render, elapsed_media, elapsed_time;
> +	u32 residency = 0;
> +
> +	cz_ts = vlv_punit_read(dev_priv, PUNIT_REG_CZ_TIMESTAMP);
> +	cz_freq_khz = DIV_ROUND_CLOSEST(dev_priv->mem_freq * 1000, 4);
> +
> +	render_count = I915_READ(VLV_RENDER_C0_COUNT_REG);
> +	media_count = I915_READ(VLV_MEDIA_C0_COUNT_REG);
> +
> +	if (rps_ei->cz_ts_ei == 0) {
> +		rps_ei->cz_ts_ei = cz_ts;
> +		rps_ei->render_ei_c0 = render_count;
> +		rps_ei->media_ei_c0 = media_count;
> +
> +		return dev_priv->rps.cur_freq;
> +	}
> +
> +	elapsed_time = cz_ts - rps_ei->cz_ts_ei;
> +	rps_ei->cz_ts_ei = cz_ts;
> +
> +	elapsed_render = render_count - rps_ei->render_ei_c0;
> +	rps_ei->render_ei_c0 = render_count;
> +
> +	elapsed_media = media_count - rps_ei->media_ei_c0;
> +	rps_ei->media_ei_c0 = media_count;
> +
> +	/* Convert all the counters into common unit of milli sec */
> +	elapsed_time /= VLV_CZ_CLOCK_TO_MILLI_SEC;
> +	elapsed_render /=  cz_freq_khz;
> +	elapsed_media /= cz_freq_khz;
> +
> +	/*
> +	 * Calculate overall C0 residency percentage
> +	 * only if elapsed time is non zero
> +	 */
> +	if (elapsed_time) {
> +		residency =
> +			((max(elapsed_render, elapsed_media) * 100)
> +				/ elapsed_time);
> +	}
> +
> +	return residency;
> +}
> +
> +
> +/**
> + * vlv_calc_delay_from_C0_counters - Increase/Decrease freq based on GPU
> + * busy-ness calculated from C0 counters of render & media power wells
> + * @dev_priv: DRM device private
> + *
> + */
> +static u32 vlv_calc_delay_from_C0_counters(struct drm_i915_private *dev_priv)
> +{
> +	u32 residency_C0_up = 0, residency_C0_down = 0;
> +	u8 new_delay, adj;
> +
> +	dev_priv->rps.ei_interrupt_count++;
> +
> +	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
> +
> +
> +	if (dev_priv->rps_up_ei.cz_ts_ei == 0) {
> +		vlv_c0_residency(dev_priv, &dev_priv->rps_up_ei);
> +		vlv_c0_residency(dev_priv, &dev_priv->rps_down_ei);
> +		return dev_priv->rps.cur_freq;
> +	}
> +
> +
> +	/*
> +	 * To down throttle, C0 residency should be less than down threshold
> +	 * for continous EI intervals. So calculate down EI counters
> +	 * once in VLV_INT_COUNT_FOR_DOWN_EI
> +	 */
> +	if (dev_priv->rps.ei_interrupt_count == VLV_INT_COUNT_FOR_DOWN_EI) {
> +
> +		dev_priv->rps.ei_interrupt_count = 0;
> +
> +		residency_C0_down = vlv_c0_residency(dev_priv,
> +						&dev_priv->rps_down_ei);
> +	} else {
> +		residency_C0_up = vlv_c0_residency(dev_priv,
> +						&dev_priv->rps_up_ei);
> +	}
> +
> +	new_delay = dev_priv->rps.cur_freq;
> +
> +	adj = dev_priv->rps.last_adj;
> +	/* C0 residency is greater than UP threshold. Increase Frequency */
> +	if (residency_C0_up >= VLV_RP_UP_EI_THRESHOLD) {
> +		if (adj > 0)
> +			adj *= 2;
> +		else
> +			adj = 1;
> +
> +		if (dev_priv->rps.cur_freq < dev_priv->rps.max_freq_softlimit)
> +			new_delay = dev_priv->rps.cur_freq + adj;
> +
> +		/*
> +		 * For better performance, jump directly
> +		 * to RPe if we're below it.
> +		 */
> +		if (new_delay < dev_priv->rps.efficient_freq)
> +			new_delay = dev_priv->rps.efficient_freq;
> +
> +	} else if (!dev_priv->rps.ei_interrupt_count &&
> +			(residency_C0_down < VLV_RP_DOWN_EI_THRESHOLD)) {
> +		if (adj < 0)
> +			adj *= 2;
> +		else
> +			adj = -1;
> +		/*
> +		 * This means, C0 residency is less than down threshold over
> +		 * a period of VLV_INT_COUNT_FOR_DOWN_EI. So, reduce the freq
> +		 */
> +		if (dev_priv->rps.cur_freq > dev_priv->rps.max_freq_softlimit)
> +			new_delay = dev_priv->rps.cur_freq + adj;
> +	}
> +
> +	return new_delay;
> +}
> +
>  static void gen6_pm_rps_work(struct work_struct *work)
>  {
>  	drm_i915_private_t *dev_priv = container_of(work, drm_i915_private_t,
> @@ -1163,6 +1289,8 @@ static void gen6_pm_rps_work(struct work_struct *work)
>  		else
>  			new_delay = dev_priv->rps.min_freq_softlimit;
>  		adj = 0;
> +	} else if (pm_iir & GEN6_PM_RP_UP_EI_EXPIRED) {
> +		new_delay = vlv_calc_delay_from_C0_counters(dev_priv);
>  	} else if (pm_iir & GEN6_PM_RP_DOWN_THRESHOLD) {
>  		if (adj < 0)
>  			adj *= 2;
> @@ -3053,6 +3181,7 @@ static void gen5_gt_irq_postinstall(struct drm_device *dev)
>  			pm_irqs |= PM_VEBOX_USER_INTERRUPT;
>  
>  		dev_priv->pm_irq_mask = 0xffffffff;
> +
>  		I915_WRITE(GEN6_PMIIR, I915_READ(GEN6_PMIIR));
>  		I915_WRITE(GEN6_PMIMR, dev_priv->pm_irq_mask);
>  		I915_WRITE(GEN6_PMIER, pm_irqs);
> @@ -4095,7 +4224,11 @@ void intel_irq_init(struct drm_device *dev)
>  	INIT_WORK(&dev_priv->l3_parity.error_work, ivybridge_parity_work);
>  
>  	/* Let's track the enabled rps events */
> -	dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS;
> +	if (IS_VALLEYVIEW(dev))
> +		/* WAUseRC0ResidenncyTurbo:VLV */

Looks like you forgot to fix the w/a comment.

Otherwise the patch looks good to me, so if you fix those two small
issues you can add:
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> +		dev_priv->pm_rps_events = GEN6_PM_RP_UP_EI_EXPIRED;
> +	else
> +		dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS;
>  
>  	setup_timer(&dev_priv->gpu_error.hangcheck_timer,
>  		    i915_hangcheck_elapsed,
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 927a7c1..e334bf1 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -506,6 +506,7 @@ enum punit_power_well {
>  #define PUNIT_REG_GPU_FREQ_STS			0xd8
>  #define   GENFREQSTATUS				(1<<0)
>  #define PUNIT_REG_MEDIA_TURBO_FREQ_REQ		0xdc
> +#define PUNIT_REG_CZ_TIMESTAMP			0xce
>  
>  #define PUNIT_FUSE_BUS2				0xf6 /* bits 47:40 */
>  #define PUNIT_FUSE_BUS1				0xf5 /* bits 55:48 */
> @@ -521,6 +522,11 @@ enum punit_power_well {
>  #define   FB_FMAX_VMIN_FREQ_LO_SHIFT		27
>  #define   FB_FMAX_VMIN_FREQ_LO_MASK		0xf8000000
>  
> +#define VLV_CZ_CLOCK_TO_MILLI_SEC		100000
> +#define VLV_RP_UP_EI_THRESHOLD			90
> +#define VLV_RP_DOWN_EI_THRESHOLD		70
> +#define VLV_INT_COUNT_FOR_DOWN_EI		5
> +
>  /* vlv2 north clock has */
>  #define CCK_FUSE_REG				0x8
>  #define  CCK_FUSE_HPLL_FREQ_MASK		0x3
> @@ -4984,6 +4990,7 @@ enum punit_power_well {
>  #define  VLV_GTLC_PW_STATUS			0x130094
>  #define VLV_GTLC_PW_RENDER_STATUS_MASK		0x80
>  #define VLV_GTLC_PW_MEDIA_STATUS_MASK		0x20
> +#define VLV_GTLC_SURVIVABILITY_REG              0x130098
>  #define  FORCEWAKE_MT				0xa188 /* multi-threaded */
>  #define   FORCEWAKE_KERNEL			0x1
>  #define   FORCEWAKE_USER			0x2
> @@ -5112,12 +5119,15 @@ enum punit_power_well {
>  #define GEN6_GT_GFX_RC6_LOCKED			0x138104
>  #define VLV_COUNTER_CONTROL			0x138104
>  #define   VLV_COUNT_RANGE_HIGH			(1<<15)
> +#define   VLV_MEDIA_RC0_COUNT_EN		(1<<5)
> +#define   VLV_RENDER_RC0_COUNT_EN		(1<<4)
>  #define   VLV_MEDIA_RC6_COUNT_EN		(1<<1)
>  #define   VLV_RENDER_RC6_COUNT_EN		(1<<0)
>  #define GEN6_GT_GFX_RC6				0x138108
>  #define GEN6_GT_GFX_RC6p			0x13810C
>  #define GEN6_GT_GFX_RC6pp			0x138110
> -
> +#define VLV_RENDER_C0_COUNT_REG		0x138118
> +#define VLV_MEDIA_C0_COUNT_REG			0x13811C
>  #define GEN6_PCODE_MAILBOX			0x138124
>  #define   GEN6_PCODE_READY			(1<<31)
>  #define   GEN6_READ_OC_PARAMS			0xc
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index b66a43b..30730be 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3097,9 +3097,13 @@ static void vlv_set_rps_idle(struct drm_i915_private *dev_priv)
>  				~VLV_GFX_CLK_FORCE_ON_BIT);
>  
>  	/* Unmask Up interrupts */
> -	dev_priv->rps.rp_up_masked = true;
> -	gen6_set_pm_mask(dev_priv, GEN6_PM_RP_DOWN_THRESHOLD,
> +	if (dev_priv->pm_rps_events & GEN6_PM_RP_UP_EI_EXPIRED)
> +		I915_WRITE(GEN6_PMINTRMSK, ~dev_priv->pm_rps_events);
> +	else {
> +		dev_priv->rps.rp_up_masked = true;
> +		gen6_set_pm_mask(dev_priv, GEN6_PM_RP_DOWN_THRESHOLD,
>  						dev_priv->rps.min_freq_softlimit);
> +	}
>  }
>  
>  void gen6_rps_idle(struct drm_i915_private *dev_priv)
> @@ -3619,6 +3623,7 @@ static void valleyview_enable_rps(struct drm_device *dev)
>  	I915_WRITE(GEN6_RP_DOWN_EI, 350000);
>  
>  	I915_WRITE(GEN6_RP_IDLE_HYSTERSIS, 10);
> +	I915_WRITE(GEN6_RP_DOWN_TIMEOUT, 0xf4240);
>  
>  	I915_WRITE(GEN6_RP_CONTROL,
>  		   GEN6_RP_MEDIA_TURBO |
> @@ -3639,9 +3644,11 @@ static void valleyview_enable_rps(struct drm_device *dev)
>  
>  	/* allows RC6 residency counter to work */
>  	I915_WRITE(VLV_COUNTER_CONTROL,
> -		   _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
> +		   _MASKED_BIT_ENABLE(VLV_MEDIA_RC0_COUNT_EN |
> +				      VLV_RENDER_RC0_COUNT_EN |
>  				      VLV_MEDIA_RC6_COUNT_EN |
>  				      VLV_RENDER_RC6_COUNT_EN));
> +
>  	if (intel_enable_rc6(dev) & INTEL_RC6_ENABLE)
>  		rc6_mode = GEN7_RC_CTL_TO_MODE | VLV_RC_CTL_CTX_RST_PARALLEL;
>  
> -- 
> 1.9.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel OTC



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