From 8f68d591d4765b2e1ce9d916ac7bc5583285c4ad Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 13 Mar 2017 17:06:17 +0000 Subject: [PATCH] drm/i915: Stop using RP_DOWN_EI on Baytrail On Baytrail, we manually calculate busyness over the evaluation interval to avoid issues with miscaluations with RC6 enabled. However, it turns out that the DOWN_EI interrupt generator is completely bust - it operates in two modes, continuous or never. Neither of which are conducive to good behaviour. Stop unmask the DOWN_EI interrupt and just compute everything from the UP_EI which does seem to correspond to the desired interval. v2: Fixup gen6_rps_pm_mask() as well v3: Inline vlv_c0_above() to combine the now identical elapsed calculation for up/down and simplify the threshold testing Fixes: 43cf3bf084ba ("drm/i915: Improved w/a for rps on Baytrail") Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: # v4.1+ Link: http://patchwork.freedesktop.org/patch/msgid/20170309211232.28878-1-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala Link: http://patchwork.freedesktop.org/patch/msgid/20170313170617.31564-1-chris@chris-wilson.co.uk (cherry picked from commit e0e8c7cb6eb68e9256de2d8cbeb481d3701c05ac) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/i915_drv.h | 2 +- drivers/gpu/drm/i915/i915_irq.c | 73 +++++++++++++-------------------- drivers/gpu/drm/i915/intel_pm.c | 5 ++- 3 files changed, 32 insertions(+), 48 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 80be09831a52..1e53c31b6826 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1325,7 +1325,7 @@ struct intel_gen6_power_mgmt { unsigned boosts; /* manual wa residency calculations */ - struct intel_rps_ei up_ei, down_ei; + struct intel_rps_ei ei; /* * Protects RPS/RC6 register access and PCU communication. diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 4fc8973744b4..b6c886ac901b 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1046,68 +1046,51 @@ static void vlv_c0_read(struct drm_i915_private *dev_priv, ei->media_c0 = I915_READ(VLV_MEDIA_C0_COUNT); } -static bool vlv_c0_above(struct drm_i915_private *dev_priv, - const struct intel_rps_ei *old, - const struct intel_rps_ei *now, - int threshold) -{ - u64 time, c0; - unsigned int mul = 100; - - if (old->cz_clock == 0) - return false; - - if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH) - mul <<= 8; - - time = now->cz_clock - old->cz_clock; - time *= threshold * dev_priv->czclk_freq; - - /* Workload can be split between render + media, e.g. SwapBuffers - * being blitted in X after being rendered in mesa. To account for - * this we need to combine both engines into our activity counter. - */ - c0 = now->render_c0 - old->render_c0; - c0 += now->media_c0 - old->media_c0; - c0 *= mul * VLV_CZ_CLOCK_TO_MILLI_SEC; - - return c0 >= time; -} - 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; + memset(&dev_priv->rps.ei, 0, sizeof(dev_priv->rps.ei)); } static u32 vlv_wa_c0_ei(struct drm_i915_private *dev_priv, u32 pm_iir) { + const struct intel_rps_ei *prev = &dev_priv->rps.ei; struct intel_rps_ei now; u32 events = 0; - if ((pm_iir & (GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_UP_EI_EXPIRED)) == 0) + if ((pm_iir & GEN6_PM_RP_UP_EI_EXPIRED) == 0) return 0; vlv_c0_read(dev_priv, &now); if (now.cz_clock == 0) return 0; - if (pm_iir & GEN6_PM_RP_DOWN_EI_EXPIRED) { - if (!vlv_c0_above(dev_priv, - &dev_priv->rps.down_ei, &now, - dev_priv->rps.down_threshold)) - events |= GEN6_PM_RP_DOWN_THRESHOLD; - dev_priv->rps.down_ei = now; - } + if (prev->cz_clock) { + u64 time, c0; + unsigned int mul; - if (pm_iir & GEN6_PM_RP_UP_EI_EXPIRED) { - if (vlv_c0_above(dev_priv, - &dev_priv->rps.up_ei, &now, - dev_priv->rps.up_threshold)) - events |= GEN6_PM_RP_UP_THRESHOLD; - dev_priv->rps.up_ei = now; + mul = VLV_CZ_CLOCK_TO_MILLI_SEC * 100; /* scale to threshold% */ + if (I915_READ(VLV_COUNTER_CONTROL) & VLV_COUNT_RANGE_HIGH) + mul <<= 8; + + time = now.cz_clock - prev->cz_clock; + time *= dev_priv->czclk_freq; + + /* Workload can be split between render + media, + * e.g. SwapBuffers being blitted in X after being rendered in + * mesa. To account for this we need to combine both engines + * into our activity counter. + */ + c0 = now.render_c0 - prev->render_c0; + c0 += now.media_c0 - prev->media_c0; + c0 *= mul; + + if (c0 > time * dev_priv->rps.up_threshold) + events = GEN6_PM_RP_UP_THRESHOLD; + else if (c0 < time * dev_priv->rps.down_threshold) + events = GEN6_PM_RP_DOWN_THRESHOLD; } + dev_priv->rps.ei = now; return events; } @@ -4228,7 +4211,7 @@ void intel_irq_init(struct drm_i915_private *dev_priv) /* Let's track the enabled rps events */ if (IS_VALLEYVIEW(dev_priv)) /* WaGsvRC0ResidencyMethod:vlv */ - dev_priv->pm_rps_events = GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_UP_EI_EXPIRED; + dev_priv->pm_rps_events = GEN6_PM_RP_UP_EI_EXPIRED; else dev_priv->pm_rps_events = GEN6_PM_RPS_EVENTS; diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 940bab22d464..6a29784d2b41 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4928,8 +4928,9 @@ static u32 gen6_rps_pm_mask(struct drm_i915_private *dev_priv, u8 val) { u32 mask = 0; + /* We use UP_EI_EXPIRED interupts for both up/down in manual mode */ if (val > dev_priv->rps.min_freq_softlimit) - mask |= GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_DOWN_THRESHOLD | GEN6_PM_RP_DOWN_TIMEOUT; + mask |= GEN6_PM_RP_UP_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_EI_EXPIRED | GEN6_PM_RP_UP_THRESHOLD; @@ -5039,7 +5040,7 @@ void gen6_rps_busy(struct drm_i915_private *dev_priv) { mutex_lock(&dev_priv->rps.hw_lock); if (dev_priv->rps.enabled) { - if (dev_priv->pm_rps_events & (GEN6_PM_RP_DOWN_EI_EXPIRED | GEN6_PM_RP_UP_EI_EXPIRED)) + if (dev_priv->pm_rps_events & GEN6_PM_RP_UP_EI_EXPIRED) gen6_rps_reset_ei(dev_priv); I915_WRITE(GEN6_PMINTRMSK, gen6_rps_pm_mask(dev_priv, dev_priv->rps.cur_freq)); -- 2.20.1