[Intel-gfx] [CI 6/9] drm/i915: Flush the RPS bottom-half when the GPU idles
Chris Wilson
chris at chris-wilson.co.uk
Mon Jul 4 07:08:36 UTC 2016
Make sure that the RPS bottom-half is flushed before we set the idle
frequency when we decide the GPU is idle. This should prevent any races
with the bottom-half and setting the idle frequency, and ensures that
the bottom-half is bounded by the GPU's rpm reference taken for when it
is active (i.e. between gen6_rps_busy() and gen6_rps_idle()).
v2: Avoid recursively using the i915->wq - RPS does not touch the
struct_mutex so has no place being on the ordered i915->wq.
v3: Enable/disable interrupts for RPS busy/idle in order to prevent
further HW access from RPS outside of the wakeref.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Imre Deak <imre.deak at intel.com>
Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
References: https://bugs.freedesktop.org/show_bug.cgi?id=89728
Reviewed-by: Michał Winiarski <michal.winiarski at intel.com>
---
drivers/gpu/drm/i915/i915_drv.c | 3 ---
drivers/gpu/drm/i915/i915_irq.c | 32 ++++++++++++--------------------
drivers/gpu/drm/i915/intel_pm.c | 11 ++++++++++-
3 files changed, 22 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 2b6494b19869..40521a3e8b8f 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2737,7 +2737,6 @@ static int intel_runtime_suspend(struct device *device)
intel_guc_suspend(dev);
- intel_suspend_gt_powersave(dev_priv);
intel_runtime_pm_disable_interrupts(dev_priv);
ret = 0;
@@ -2852,8 +2851,6 @@ static int intel_runtime_resume(struct device *device)
if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv))
intel_hpd_init(dev_priv);
- intel_enable_gt_powersave(dev_priv);
-
enable_rpm_wakeref_asserts(dev_priv);
if (ret)
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 80d162acda1b..f0535df41dfd 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -351,9 +351,8 @@ void gen6_reset_rps_interrupts(struct drm_i915_private *dev_priv)
void gen6_enable_rps_interrupts(struct drm_i915_private *dev_priv)
{
spin_lock_irq(&dev_priv->irq_lock);
-
- WARN_ON(dev_priv->rps.pm_iir);
- WARN_ON(I915_READ(gen6_pm_iir(dev_priv)) & dev_priv->pm_rps_events);
+ WARN_ON_ONCE(dev_priv->rps.pm_iir);
+ WARN_ON_ONCE(I915_READ(gen6_pm_iir(dev_priv)) & dev_priv->pm_rps_events);
dev_priv->rps.interrupts_enabled = true;
I915_WRITE(gen6_pm_ier(dev_priv), I915_READ(gen6_pm_ier(dev_priv)) |
dev_priv->pm_rps_events);
@@ -371,11 +370,6 @@ void gen6_disable_rps_interrupts(struct drm_i915_private *dev_priv)
{
spin_lock_irq(&dev_priv->irq_lock);
dev_priv->rps.interrupts_enabled = false;
- spin_unlock_irq(&dev_priv->irq_lock);
-
- cancel_work_sync(&dev_priv->rps.work);
-
- spin_lock_irq(&dev_priv->irq_lock);
I915_WRITE(GEN6_PMINTRMSK, gen6_sanitize_rps_pm_mask(dev_priv, ~0));
@@ -384,8 +378,15 @@ void gen6_disable_rps_interrupts(struct drm_i915_private *dev_priv)
~dev_priv->pm_rps_events);
spin_unlock_irq(&dev_priv->irq_lock);
-
synchronize_irq(dev_priv->dev->irq);
+
+ /* Now that we will not be generating any more work, flush any
+ * outsanding tasks. As we are called on the RPS idle path,
+ * we will reset the GPU to minimum frequencies, so the current
+ * state of the worker can be discarded.
+ */
+ cancel_work_sync(&dev_priv->rps.work);
+ gen6_reset_rps_interrupts(dev_priv);
}
/**
@@ -1082,13 +1083,6 @@ static void gen6_pm_rps_work(struct work_struct *work)
return;
}
- /*
- * The RPS work is synced during runtime suspend, we don't require a
- * wakeref. TODO: instead of disabling the asserts make sure that we
- * always hold an RPM reference while the work is running.
- */
- DISABLE_RPM_WAKEREF_ASSERTS(dev_priv);
-
pm_iir = dev_priv->rps.pm_iir;
dev_priv->rps.pm_iir = 0;
/* Make sure not to corrupt PMIMR state used by ringbuffer on GEN6 */
@@ -1101,7 +1095,7 @@ static void gen6_pm_rps_work(struct work_struct *work)
WARN_ON(pm_iir & ~dev_priv->pm_rps_events);
if ((pm_iir & dev_priv->pm_rps_events) == 0 && !client_boost)
- goto out;
+ return;
mutex_lock(&dev_priv->rps.hw_lock);
@@ -1156,8 +1150,6 @@ static void gen6_pm_rps_work(struct work_struct *work)
intel_set_rps(dev_priv, new_delay);
mutex_unlock(&dev_priv->rps.hw_lock);
-out:
- ENABLE_RPM_WAKEREF_ASSERTS(dev_priv);
}
@@ -1597,7 +1589,7 @@ static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir)
gen6_disable_pm_irq(dev_priv, pm_iir & dev_priv->pm_rps_events);
if (dev_priv->rps.interrupts_enabled) {
dev_priv->rps.pm_iir |= pm_iir & dev_priv->pm_rps_events;
- queue_work(dev_priv->wq, &dev_priv->rps.work);
+ schedule_work(&dev_priv->rps.work);
}
spin_unlock(&dev_priv->irq_lock);
}
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 48e21c729eb0..814b0dfaf640 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4864,6 +4864,8 @@ void gen6_rps_busy(struct drm_i915_private *dev_priv)
I915_WRITE(GEN6_PMINTRMSK,
gen6_rps_pm_mask(dev_priv, dev_priv->rps.cur_freq));
+ gen6_enable_rps_interrupts(dev_priv);
+
/* Ensure we start at the user's desired frequency */
intel_set_rps(dev_priv,
clamp(dev_priv->rps.cur_freq,
@@ -4875,6 +4877,13 @@ void gen6_rps_busy(struct drm_i915_private *dev_priv)
void gen6_rps_idle(struct drm_i915_private *dev_priv)
{
+ /* Flush our bottom-half so that it does not race with us
+ * setting the idle frequency and so that it is bounded by
+ * our rpm wakeref. And then disable the interrupts to stop any
+ * futher RPS reclocking whilst we are asleep.
+ */
+ gen6_disable_rps_interrupts(dev_priv);
+
mutex_lock(&dev_priv->rps.hw_lock);
if (dev_priv->rps.enabled) {
if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
@@ -4915,7 +4924,7 @@ void gen6_rps_boost(struct drm_i915_private *dev_priv,
spin_lock_irq(&dev_priv->irq_lock);
if (dev_priv->rps.interrupts_enabled) {
dev_priv->rps.client_boost = true;
- queue_work(dev_priv->wq, &dev_priv->rps.work);
+ schedule_work(&dev_priv->rps.work);
}
spin_unlock_irq(&dev_priv->irq_lock);
--
2.8.1
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