[PATCH v2 08/25] drm/i915: get a runtime PM ref for the deferred GT powersave enabling

Imre Deak
2014-04-14T17:25:22Z

At least on VLV but probably on other platforms too we depend on RC6
being enabled for RPM, so disable RPM until the delayed RC6 enabling
completes.

v2:
- explain the reason for the _noresume version of RPM get (Daniel)
- use the simpler 'if (schedule_work()) rpm_get();' instead of
'if (!cancel_work_sync()) rpm_get(); schedule_work();'

Signed-off-by: Imre Deak <imre.deak@intel.com>
---
drivers/gpu/drm/i915/i915_drv.c | 5 ++++-
drivers/gpu/drm/i915/intel_drv.h | 2 ++
drivers/gpu/drm/i915/intel_pm.c | 34 ++++++++++++++++++++++++++++++++--
3 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index a821608..a20d2d1 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -754,7 +754,7 @@ int i915_reset(struct drm_device *dev)
* previous concerns that it doesn't respond well to some forms
* of re-init after reset. */
if (INTEL_INFO(dev)->gen > 5)
- intel_enable_gt_powersave(dev);
+ intel_reset_gt_powersave(dev);

intel_hpd_init(dev);
} else {
@@ -923,6 +923,9 @@ static int intel_runtime_suspend(struct device *device)
struct drm_device *dev = pci_get_drvdata(pdev);
struct drm_i915_private *dev_priv = dev->dev_private;

+ if (WARN_ON_ONCE(!dev_priv->rps.enabled))
+ return -ENODEV;
+
WARN_ON(!HAS_RUNTIME_PM(dev));
assert_force_wake_inactive(dev_priv);

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index c551472..618d05a 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -924,6 +924,7 @@ void intel_init_gt_powersave(struct drm_device *dev);
void intel_cleanup_gt_powersave(struct drm_device *dev);
void intel_enable_gt_powersave(struct drm_device *dev);
void intel_disable_gt_powersave(struct drm_device *dev);
+void intel_reset_gt_powersave(struct drm_device *dev);
void ironlake_teardown_rc6(struct drm_device *dev);
void gen6_update_ring_freq(struct drm_device *dev);
void gen6_rps_idle(struct drm_i915_private *dev_priv);
@@ -931,6 +932,7 @@ void gen6_rps_boost(struct drm_i915_private *dev_priv);
void intel_aux_display_runtime_get(struct drm_i915_private *dev_priv);
void intel_aux_display_runtime_put(struct drm_i915_private *dev_priv);
void intel_runtime_pm_get(struct drm_i915_private *dev_priv);
+void intel_runtime_pm_get_noresume(struct drm_i915_private *dev_priv);
void intel_runtime_pm_put(struct drm_i915_private *dev_priv);
void intel_init_runtime_pm(struct drm_i915_private *dev_priv);
void intel_fini_runtime_pm(struct drm_i915_private *dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index e5b9f08..0e8b263 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4549,6 +4549,8 @@ static void intel_gen6_powersave_work(struct work_struct *work)
}
dev_priv->rps.enabled = true;
mutex_unlock(&dev_priv->rps.hw_lock);
+
+ intel_runtime_pm_put(dev_priv);
}

void intel_enable_gt_powersave(struct drm_device *dev)
@@ -4566,12 +4568,28 @@ void intel_enable_gt_powersave(struct drm_device *dev)
* PCU communication is slow and this doesn't need to be
* done at any specific time, so do this out of our fast path
* to make resume and init faster.
+ *
+ * We depend on the HW RC6 power context save/restore
+ * mechanism when entering D3 through runtime PM suspend. So
+ * disable RPM until RPS/RC6 is properly setup. We can only
+ * get here via the driver load/system resume/runtime resume
+ * paths, so the _noresume version is enough (and in case of
+ * runtime resume it's necessary).
*/
- schedule_delayed_work(&dev_priv->rps.delayed_resume_work,
- round_jiffies_up_relative(HZ));
+ if (schedule_delayed_work(&dev_priv->rps.delayed_resume_work,
+ round_jiffies_up_relative(HZ)))
+ intel_runtime_pm_get_noresume(dev_priv);
}
}

+void intel_reset_gt_powersave(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ dev_priv->rps.enabled = false;
+ intel_enable_gt_powersave(dev);
+}
+
static void ibx_init_clock_gating(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -6025,6 +6043,18 @@ void intel_runtime_pm_get(struct drm_i915_private *dev_priv)
WARN(dev_priv->pm.suspended, "Device still suspended.\n");
}

+void intel_runtime_pm_get_noresume(struct drm_i915_private *dev_priv)
+{
+ struct drm_device *dev = dev_priv->dev;
+ struct device *device = &dev->pdev->dev;
+
+ if (!HAS_RUNTIME_PM(dev))
+ return;
+
+ WARN(dev_priv->pm.suspended, "Getting nosync-ref while suspended.\n");
+ pm_runtime_get_noresume(device);
+}
+
void intel_runtime_pm_put(struct drm_i915_private *dev_priv)
{
struct drm_device *dev = dev_priv->dev;
--
1.8.4