drm/i915: Use down ei for manual Baytrail RPS calculations

Use both up/down manual ei calcuations for symmetry and greater
flexibility for reclocking, instead of faking the down interrupt based
on a fixed integer number of up interrupts.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Deepak S<deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1031,8 +1031,6 @@ struct intel_gen6_power_mgmt {
 	u8 rp0_freq;		/* Non-overclocked max frequency. */
 	u32 cz_freq;
 
-	u32 ei_interrupt_count;
-
 	int last_adj;
 	enum { LOW_POWER, BETWEEN, HIGH_POWER } power;
 

drivers/gpu/drm/i915/i915_irq.c

@@ -1033,7 +1033,6 @@ void gen6_rps_reset_ei(struct drm_i915_private *dev_priv)
 {
 	vlv_c0_read(dev_priv, &dev_priv->rps.down_ei);
 	dev_priv->rps.up_ei = dev_priv->rps.down_ei;
-	dev_priv->rps.ei_interrupt_count = 0;
 }
 
 static u32 vlv_wa_c0_ei(struct drm_i915_private *dev_priv, u32 pm_iir)
@@ -1041,23 +1040,13 @@ static u32 vlv_wa_c0_ei(struct drm_i915_private *dev_priv, u32 pm_iir)
 	struct intel_rps_ei now;
 	u32 events = 0;
 
-	if ((pm_iir & GEN6_PM_RP_UP_EI_EXPIRED) == 0)
+	if ((pm_iir & (GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_UP_EI_EXPIRED)) == 0)
 		return 0;
 
 	vlv_c0_read(dev_priv, &now);
 	if (now.cz_clock == 0)
 		return 0;
 
-	/*
-	 * 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) {
-		pm_iir |= GEN6_PM_RP_DOWN_EI_EXPIRED;
-		dev_priv->rps.ei_interrupt_count = 0;
-	}
-
 	if (pm_iir & GEN6_PM_RP_DOWN_EI_EXPIRED) {
 		if (!vlv_c0_above(dev_priv,
 				  &dev_priv->rps.down_ei, &now,
@@ -4254,7 +4243,7 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
 	/* Let's track the enabled rps events */
 	if (IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv))
 		/* WaGsvRC0ResidencyMethod:vlv */
-		dev_priv->pm_rps_events = GEN6_PM_RP_UP_EI_EXPIRED;
+		dev_priv->pm_rps_events = GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_UP_EI_EXPIRED;
 	else
 		dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS;
 

drivers/gpu/drm/i915/i915_reg.h

@@ -673,7 +673,6 @@ enum skl_disp_power_wells {
 #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

drivers/gpu/drm/i915/intel_pm.c

@@ -3922,11 +3922,10 @@ static u32 gen6_rps_pm_mask(struct drm_i915_private *dev_priv, u8 val)
 	u32 mask = 0;
 
 	if (val > dev_priv->rps.min_freq_softlimit)
-		mask |= GEN6_PM_RP_DOWN_THRESHOLD | GEN6_PM_RP_DOWN_TIMEOUT;
+		mask |= GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_DOWN_THRESHOLD | GEN6_PM_RP_DOWN_TIMEOUT;
 	if (val < dev_priv->rps.max_freq_softlimit)
-		mask |= GEN6_PM_RP_UP_THRESHOLD;
+		mask |= GEN6_PM_RP_UP_EI_EXPIRED | GEN6_PM_RP_UP_THRESHOLD;
 
-	mask |= dev_priv->pm_rps_events & (GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_UP_EI_EXPIRED);
 	mask &= dev_priv->pm_rps_events;
 
 	return gen6_sanitize_rps_pm_mask(dev_priv, ~mask);