Atm, we assert that the device is not suspended until the point when the
device is truly put to a suspended state. This is fine, but we can catch
more problems if we check that RPM refcount is non-zero. After that one
drops to zero we shouldn't access the device any more, even if the actual
device suspend may be delayed. Change assert_rpm_wakelock_held()
accordingly to check for a non-zero RPM refcount in addition to the
current device-not-suspended check.
For the new asserts to work we need to annotate every place explicitly in
the code where we expect that the device is powered. The places where we
only assume this, but may not hold an RPM reference:
- driver load
We assume the device to be powered until we enable RPM. Make this
explicit by taking an RPM reference around the load function.
- system and runtime sudpend/resume handlers
These handlers are called when the RPM reference becomes 0 and know the
exact point after which the device can get powered off. Disable the
RPM-reference-held check for their duration.
- the IRQ, hangcheck and RPS work handlers
These handlers are flushed in the system/runtime suspend handler
before the device is powered off, so it's guaranteed that they won't
run while the device is powered off even though they don't hold any
RPM reference. Disable the RPM-reference-held check for their duration.
In all these cases we still check that the device is not suspended.
These explicit annotations also have the positive side effect of
documenting our assumptions better.
This caught additional WARNs from the atomic modeset path, those should
be fixed separately.
v2:
- remove the redundant HAS_RUNTIME_PM check (moved to patch 1) (Ville)
v3:
- use a new dedicated RPM wakelock refcount to also catch cases where
our own RPM get/put functions were not called (Chris)
- assert also that the new RPM wakelock refcount is 0 in the RPM
suspend handler (Chris)
- change the assert error message to be more meaningful (Chris)
- prevent false assert errors and check that the RPM wakelock is 0 in
the RPM resume handler too
- prevent false assert errors in the hangcheck work too
- add a device not suspended assert check to the hangcheck work
v4:
- rename disable/enable_rpm_asserts to disable/enable_rpm_wakeref_asserts
and wakelock_count to wakeref_count
- disable the wakeref asserts in the IRQ handlers and RPS work too
- update/clarify commit message
v5:
- mark places we plan to change to use proper RPM refcounting with
separate DISABLE/ENABLE_RPM_WAKEREF_ASSERTS aliases (Chris)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1450227139-13471-1-git-send-email-imre.deak@intel.com
intel_pm_setup(dev);
+ intel_runtime_pm_get(dev_priv);
+
intel_display_crc_init(dev);
i915_dump_device_info(dev_priv);
i915_audio_component_init(dev_priv);
+ intel_runtime_pm_put(dev_priv);
+
return 0;
out_power_well:
kmem_cache_destroy(dev_priv->requests);
kmem_cache_destroy(dev_priv->vmas);
kmem_cache_destroy(dev_priv->objects);
+
+ intel_runtime_pm_put(dev_priv);
+
kfree(dev_priv);
return ret;
}
dev_priv->modeset_restore = MODESET_SUSPENDED;
mutex_unlock(&dev_priv->modeset_restore_lock);
+ disable_rpm_wakeref_asserts(dev_priv);
+
/* We do a lot of poking in a lot of registers, make sure they work
* properly. */
intel_display_set_init_power(dev_priv, true);
if (error) {
dev_err(&dev->pdev->dev,
"GEM idle failed, resume might fail\n");
- return error;
+ goto out;
}
intel_guc_suspend(dev);
if (HAS_CSR(dev_priv))
flush_work(&dev_priv->csr.work);
- return 0;
+out:
+ enable_rpm_wakeref_asserts(dev_priv);
+
+ return error;
}
static int i915_drm_suspend_late(struct drm_device *drm_dev, bool hibernation)
bool fw_csr;
int ret;
+ disable_rpm_wakeref_asserts(dev_priv);
+
fw_csr = suspend_to_idle(dev_priv) && dev_priv->csr.dmc_payload;
/*
* In case of firmware assisted context save/restore don't manually
if (!fw_csr)
intel_power_domains_init_hw(dev_priv, true);
- return ret;
+ goto out;
}
pci_disable_device(drm_dev->pdev);
dev_priv->suspended_to_idle = suspend_to_idle(dev_priv);
- return 0;
+out:
+ enable_rpm_wakeref_asserts(dev_priv);
+
+ return ret;
}
int i915_suspend_switcheroo(struct drm_device *dev, pm_message_t state)
{
struct drm_i915_private *dev_priv = dev->dev_private;
+ disable_rpm_wakeref_asserts(dev_priv);
+
mutex_lock(&dev->struct_mutex);
i915_gem_restore_gtt_mappings(dev);
mutex_unlock(&dev->struct_mutex);
drm_kms_helper_poll_enable(dev);
+ enable_rpm_wakeref_asserts(dev_priv);
+
return 0;
}
pci_set_master(dev->pdev);
+ disable_rpm_wakeref_asserts(dev_priv);
+
if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
ret = vlv_resume_prepare(dev_priv, false);
if (ret)
out:
dev_priv->suspended_to_idle = false;
+ enable_rpm_wakeref_asserts(dev_priv);
+
return ret;
}
return -EAGAIN;
}
+
+ disable_rpm_wakeref_asserts(dev_priv);
+
/*
* We are safe here against re-faults, since the fault handler takes
* an RPM reference.
DRM_ERROR("Runtime suspend failed, disabling it (%d)\n", ret);
intel_runtime_pm_enable_interrupts(dev_priv);
+ enable_rpm_wakeref_asserts(dev_priv);
+
return ret;
}
intel_uncore_forcewake_reset(dev, false);
+
+ enable_rpm_wakeref_asserts(dev_priv);
+ WARN_ON_ONCE(atomic_read(&dev_priv->pm.wakeref_count));
dev_priv->pm.suspended = true;
/*
DRM_DEBUG_KMS("Resuming device\n");
+ WARN_ON_ONCE(atomic_read(&dev_priv->pm.wakeref_count));
+ disable_rpm_wakeref_asserts(dev_priv);
+
intel_opregion_notify_adapter(dev, PCI_D0);
dev_priv->pm.suspended = false;
intel_enable_gt_powersave(dev);
+ enable_rpm_wakeref_asserts(dev_priv);
+
if (ret)
DRM_ERROR("Runtime resume failed, disabling it (%d)\n", ret);
else
* For more, read the Documentation/power/runtime_pm.txt.
*/
struct i915_runtime_pm {
+ atomic_t wakeref_count;
bool suspended;
bool irqs_enabled;
};
spin_unlock_irq(&dev_priv->irq_lock);
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 */
WARN_ON(pm_iir & ~dev_priv->pm_rps_events);
if ((pm_iir & dev_priv->pm_rps_events) == 0 && !client_boost)
- return;
+ goto out;
mutex_lock(&dev_priv->rps.hw_lock);
intel_set_rps(dev_priv->dev, new_delay);
mutex_unlock(&dev_priv->rps.hw_lock);
+out:
+ ENABLE_RPM_WAKEREF_ASSERTS(dev_priv);
}
if (!intel_irqs_enabled(dev_priv))
return IRQ_NONE;
+ /* IRQs are synced during runtime_suspend, we don't require a wakeref */
+ disable_rpm_wakeref_asserts(dev_priv);
+
while (true) {
/* Find, clear, then process each source of interrupt */
}
out:
+ enable_rpm_wakeref_asserts(dev_priv);
+
return ret;
}
if (!intel_irqs_enabled(dev_priv))
return IRQ_NONE;
+ /* IRQs are synced during runtime_suspend, we don't require a wakeref */
+ disable_rpm_wakeref_asserts(dev_priv);
+
for (;;) {
master_ctl = I915_READ(GEN8_MASTER_IRQ) & ~GEN8_MASTER_IRQ_CONTROL;
iir = I915_READ(VLV_IIR);
POSTING_READ(GEN8_MASTER_IRQ);
}
+ enable_rpm_wakeref_asserts(dev_priv);
+
return ret;
}
if (!intel_irqs_enabled(dev_priv))
return IRQ_NONE;
+ /* IRQs are synced during runtime_suspend, we don't require a wakeref */
+ disable_rpm_wakeref_asserts(dev_priv);
+
/* We get interrupts on unclaimed registers, so check for this before we
* do any I915_{READ,WRITE}. */
intel_uncore_check_errors(dev);
POSTING_READ(SDEIER);
}
+ /* IRQs are synced during runtime_suspend, we don't require a wakeref */
+ enable_rpm_wakeref_asserts(dev_priv);
+
return ret;
}
if (!intel_irqs_enabled(dev_priv))
return IRQ_NONE;
+ /* IRQs are synced during runtime_suspend, we don't require a wakeref */
+ disable_rpm_wakeref_asserts(dev_priv);
+
if (INTEL_INFO(dev_priv)->gen >= 9)
aux_mask |= GEN9_AUX_CHANNEL_B | GEN9_AUX_CHANNEL_C |
GEN9_AUX_CHANNEL_D;
master_ctl = I915_READ_FW(GEN8_MASTER_IRQ);
master_ctl &= ~GEN8_MASTER_IRQ_CONTROL;
if (!master_ctl)
- return IRQ_NONE;
+ goto out;
I915_WRITE_FW(GEN8_MASTER_IRQ, 0);
I915_WRITE_FW(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL);
POSTING_READ_FW(GEN8_MASTER_IRQ);
+out:
+ enable_rpm_wakeref_asserts(dev_priv);
+
return ret;
}
if (!i915.enable_hangcheck)
return;
+ /*
+ * The hangcheck work is synced during runtime suspend, we don't
+ * require a wakeref. TODO: instead of disabling the asserts make
+ * sure that we hold a reference when this work is running.
+ */
+ DISABLE_RPM_WAKEREF_ASSERTS(dev_priv);
+
for_each_ring(ring, dev_priv, i) {
u64 acthd;
u32 seqno;
}
}
- if (rings_hung)
- return i915_handle_error(dev, true, "Ring hung");
+ if (rings_hung) {
+ i915_handle_error(dev, true, "Ring hung");
+ goto out;
+ }
if (busy_count)
/* Reset timer case chip hangs without another request
* being added */
i915_queue_hangcheck(dev);
+
+out:
+ ENABLE_RPM_WAKEREF_ASSERTS(dev_priv);
}
void i915_queue_hangcheck(struct drm_device *dev)
u16 flip_mask =
I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;
+ irqreturn_t ret;
if (!intel_irqs_enabled(dev_priv))
return IRQ_NONE;
+ /* IRQs are synced during runtime_suspend, we don't require a wakeref */
+ disable_rpm_wakeref_asserts(dev_priv);
+
+ ret = IRQ_NONE;
iir = I915_READ16(IIR);
if (iir == 0)
- return IRQ_NONE;
+ goto out;
while (iir & ~flip_mask) {
/* Can't rely on pipestat interrupt bit in iir as it might
iir = new_iir;
}
+ ret = IRQ_HANDLED;
+
+out:
+ enable_rpm_wakeref_asserts(dev_priv);
- return IRQ_HANDLED;
+ return ret;
}
static void i8xx_irq_uninstall(struct drm_device * dev)
if (!intel_irqs_enabled(dev_priv))
return IRQ_NONE;
+ /* IRQs are synced during runtime_suspend, we don't require a wakeref */
+ disable_rpm_wakeref_asserts(dev_priv);
+
iir = I915_READ(IIR);
do {
bool irq_received = (iir & ~flip_mask) != 0;
iir = new_iir;
} while (iir & ~flip_mask);
+ enable_rpm_wakeref_asserts(dev_priv);
+
return ret;
}
if (!intel_irqs_enabled(dev_priv))
return IRQ_NONE;
+ /* IRQs are synced during runtime_suspend, we don't require a wakeref */
+ disable_rpm_wakeref_asserts(dev_priv);
+
iir = I915_READ(IIR);
for (;;) {
iir = new_iir;
}
+ enable_rpm_wakeref_asserts(dev_priv);
+
return ret;
}
assert_rpm_wakelock_held(struct drm_i915_private *dev_priv)
{
assert_rpm_device_not_suspended(dev_priv);
+ WARN_ONCE(!atomic_read(&dev_priv->pm.wakeref_count),
+ "RPM wakelock ref not held during HW access");
}
+/**
+ * disable_rpm_wakeref_asserts - disable the RPM assert checks
+ * @dev_priv: i915 device instance
+ *
+ * This function disable asserts that check if we hold an RPM wakelock
+ * reference, while keeping the device-not-suspended checks still enabled.
+ * It's meant to be used only in special circumstances where our rule about
+ * the wakelock refcount wrt. the device power state doesn't hold. According
+ * to this rule at any point where we access the HW or want to keep the HW in
+ * an active state we must hold an RPM wakelock reference acquired via one of
+ * the intel_runtime_pm_get() helpers. Currently there are a few special spots
+ * where this rule doesn't hold: the IRQ and suspend/resume handlers, the
+ * forcewake release timer, and the GPU RPS and hangcheck works. All other
+ * users should avoid using this function.
+ *
+ * Any calls to this function must have a symmetric call to
+ * enable_rpm_wakeref_asserts().
+ */
+static inline void
+disable_rpm_wakeref_asserts(struct drm_i915_private *dev_priv)
+{
+ atomic_inc(&dev_priv->pm.wakeref_count);
+}
+
+/**
+ * enable_rpm_wakeref_asserts - re-enable the RPM assert checks
+ * @dev_priv: i915 device instance
+ *
+ * This function re-enables the RPM assert checks after disabling them with
+ * disable_rpm_wakeref_asserts. It's meant to be used only in special
+ * circumstances otherwise its use should be avoided.
+ *
+ * Any calls to this function must have a symmetric call to
+ * disable_rpm_wakeref_asserts().
+ */
+static inline void
+enable_rpm_wakeref_asserts(struct drm_i915_private *dev_priv)
+{
+ atomic_dec(&dev_priv->pm.wakeref_count);
+}
+
+/* TODO: convert users of these to rely instead on proper RPM refcounting */
+#define DISABLE_RPM_WAKEREF_ASSERTS(dev_priv) \
+ disable_rpm_wakeref_asserts(dev_priv)
+
+#define ENABLE_RPM_WAKEREF_ASSERTS(dev_priv) \
+ enable_rpm_wakeref_asserts(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);
INIT_LIST_HEAD(&dev_priv->rps.mmioflips.link);
dev_priv->pm.suspended = false;
+ atomic_set(&dev_priv->pm.wakeref_count, 0);
}
struct device *device = &dev->pdev->dev;
pm_runtime_get_sync(device);
+
+ atomic_inc(&dev_priv->pm.wakeref_count);
assert_rpm_wakelock_held(dev_priv);
}
assert_rpm_wakelock_held(dev_priv);
pm_runtime_get_noresume(device);
+
+ atomic_inc(&dev_priv->pm.wakeref_count);
}
/**
struct drm_device *dev = dev_priv->dev;
struct device *device = &dev->pdev->dev;
+ atomic_dec(&dev_priv->pm.wakeref_count);
+
pm_runtime_mark_last_busy(device);
pm_runtime_put_autosuspend(device);
}
projects / openwrt / staging / blogic.git / commitdiff