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drm/i915: Track the wakeref used to initialise display power domains
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On module load and unload, we grab the POWER_DOMAIN_INIT powerwells and
transfer them to the runtime-pm code. We can use our wakeref tracking to
verify that the wakeref is indeed passed from init to enable, and
disable to fini; and across suspend.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-17-chris@chris-wilson.co.uk
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Chris Wilson committed Jan 14, 2019
1 parent 0e6e0be commit 25c896b
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Showing 3 changed files with 88 additions and 68 deletions.
3 changes: 3 additions & 0 deletions drivers/gpu/drm/i915/i915_debugfs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2699,6 +2699,9 @@ static int i915_runtime_pm_status(struct seq_file *m, void *unused)
if (!HAS_RUNTIME_PM(dev_priv))
seq_puts(m, "Runtime power management not supported\n");

seq_printf(m, "Runtime power status: %s\n",
enableddisabled(!dev_priv->power_domains.wakeref));

seq_printf(m, "GPU idle: %s (epoch %u)\n",
yesno(!dev_priv->gt.awake), dev_priv->gt.epoch);
seq_printf(m, "IRQs disabled: %s\n",
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2 changes: 2 additions & 0 deletions drivers/gpu/drm/i915/i915_drv.h
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Original file line number Diff line number Diff line change
Expand Up @@ -822,6 +822,8 @@ struct i915_power_domains {
bool display_core_suspended;
int power_well_count;

intel_wakeref_t wakeref;

struct mutex lock;
int domain_use_count[POWER_DOMAIN_NUM];
struct i915_power_well *power_wells;
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151 changes: 83 additions & 68 deletions drivers/gpu/drm/i915/intel_runtime_pm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3997,7 +3997,7 @@ static void intel_power_domains_verify_state(struct drm_i915_private *dev_priv);

/**
* intel_power_domains_init_hw - initialize hardware power domain state
* @dev_priv: i915 device instance
* @i915: i915 device instance
* @resume: Called from resume code paths or not
*
* This function initializes the hardware power domain state and enables all
Expand All @@ -4011,49 +4011,52 @@ static void intel_power_domains_verify_state(struct drm_i915_private *dev_priv);
* intel_power_domains_enable()) and must be paired with
* intel_power_domains_fini_hw().
*/
void intel_power_domains_init_hw(struct drm_i915_private *dev_priv, bool resume)
void intel_power_domains_init_hw(struct drm_i915_private *i915, bool resume)
{
struct i915_power_domains *power_domains = &dev_priv->power_domains;
struct i915_power_domains *power_domains = &i915->power_domains;

power_domains->initializing = true;

if (IS_ICELAKE(dev_priv)) {
icl_display_core_init(dev_priv, resume);
} else if (IS_CANNONLAKE(dev_priv)) {
cnl_display_core_init(dev_priv, resume);
} else if (IS_GEN9_BC(dev_priv)) {
skl_display_core_init(dev_priv, resume);
} else if (IS_GEN9_LP(dev_priv)) {
bxt_display_core_init(dev_priv, resume);
} else if (IS_CHERRYVIEW(dev_priv)) {
if (IS_ICELAKE(i915)) {
icl_display_core_init(i915, resume);
} else if (IS_CANNONLAKE(i915)) {
cnl_display_core_init(i915, resume);
} else if (IS_GEN9_BC(i915)) {
skl_display_core_init(i915, resume);
} else if (IS_GEN9_LP(i915)) {
bxt_display_core_init(i915, resume);
} else if (IS_CHERRYVIEW(i915)) {
mutex_lock(&power_domains->lock);
chv_phy_control_init(dev_priv);
chv_phy_control_init(i915);
mutex_unlock(&power_domains->lock);
} else if (IS_VALLEYVIEW(dev_priv)) {
} else if (IS_VALLEYVIEW(i915)) {
mutex_lock(&power_domains->lock);
vlv_cmnlane_wa(dev_priv);
vlv_cmnlane_wa(i915);
mutex_unlock(&power_domains->lock);
} else if (IS_IVYBRIDGE(dev_priv) || INTEL_GEN(dev_priv) >= 7)
intel_pch_reset_handshake(dev_priv, !HAS_PCH_NOP(dev_priv));
} else if (IS_IVYBRIDGE(i915) || INTEL_GEN(i915) >= 7) {
intel_pch_reset_handshake(i915, !HAS_PCH_NOP(i915));
}

/*
* Keep all power wells enabled for any dependent HW access during
* initialization and to make sure we keep BIOS enabled display HW
* resources powered until display HW readout is complete. We drop
* this reference in intel_power_domains_enable().
*/
intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
power_domains->wakeref =
intel_display_power_get(i915, POWER_DOMAIN_INIT);

/* Disable power support if the user asked so. */
if (!i915_modparams.disable_power_well)
intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
intel_power_domains_sync_hw(dev_priv);
intel_display_power_get(i915, POWER_DOMAIN_INIT);
intel_power_domains_sync_hw(i915);

power_domains->initializing = false;
}

/**
* intel_power_domains_fini_hw - deinitialize hw power domain state
* @dev_priv: i915 device instance
* @i915: i915 device instance
*
* De-initializes the display power domain HW state. It also ensures that the
* device stays powered up so that the driver can be reloaded.
Expand All @@ -4062,21 +4065,24 @@ void intel_power_domains_init_hw(struct drm_i915_private *dev_priv, bool resume)
* intel_power_domains_disable()) and must be paired with
* intel_power_domains_init_hw().
*/
void intel_power_domains_fini_hw(struct drm_i915_private *dev_priv)
void intel_power_domains_fini_hw(struct drm_i915_private *i915)
{
/* Keep the power well enabled, but cancel its rpm wakeref. */
intel_runtime_pm_put_unchecked(dev_priv);
intel_wakeref_t wakeref __maybe_unused =
fetch_and_zero(&i915->power_domains.wakeref);

/* Remove the refcount we took to keep power well support disabled. */
if (!i915_modparams.disable_power_well)
intel_display_power_put_unchecked(dev_priv, POWER_DOMAIN_INIT);
intel_display_power_put_unchecked(i915, POWER_DOMAIN_INIT);

intel_power_domains_verify_state(i915);

intel_power_domains_verify_state(dev_priv);
/* Keep the power well enabled, but cancel its rpm wakeref. */
intel_runtime_pm_put(i915, wakeref);
}

/**
* intel_power_domains_enable - enable toggling of display power wells
* @dev_priv: i915 device instance
* @i915: i915 device instance
*
* Enable the ondemand enabling/disabling of the display power wells. Note that
* power wells not belonging to POWER_DOMAIN_INIT are allowed to be toggled
Expand All @@ -4086,30 +4092,36 @@ void intel_power_domains_fini_hw(struct drm_i915_private *dev_priv)
* of display HW readout (which will acquire the power references reflecting
* the current HW state).
*/
void intel_power_domains_enable(struct drm_i915_private *dev_priv)
void intel_power_domains_enable(struct drm_i915_private *i915)
{
intel_display_power_put_unchecked(dev_priv, POWER_DOMAIN_INIT);
intel_wakeref_t wakeref __maybe_unused =
fetch_and_zero(&i915->power_domains.wakeref);

intel_power_domains_verify_state(dev_priv);
intel_display_power_put(i915, POWER_DOMAIN_INIT, wakeref);
intel_power_domains_verify_state(i915);
}

/**
* intel_power_domains_disable - disable toggling of display power wells
* @dev_priv: i915 device instance
* @i915: i915 device instance
*
* Disable the ondemand enabling/disabling of the display power wells. See
* intel_power_domains_enable() for which power wells this call controls.
*/
void intel_power_domains_disable(struct drm_i915_private *dev_priv)
void intel_power_domains_disable(struct drm_i915_private *i915)
{
intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
struct i915_power_domains *power_domains = &i915->power_domains;

intel_power_domains_verify_state(dev_priv);
WARN_ON(power_domains->wakeref);
power_domains->wakeref =
intel_display_power_get(i915, POWER_DOMAIN_INIT);

intel_power_domains_verify_state(i915);
}

/**
* intel_power_domains_suspend - suspend power domain state
* @dev_priv: i915 device instance
* @i915: i915 device instance
* @suspend_mode: specifies the target suspend state (idle, mem, hibernation)
*
* This function prepares the hardware power domain state before entering
Expand All @@ -4118,12 +4130,14 @@ void intel_power_domains_disable(struct drm_i915_private *dev_priv)
* It must be called with power domains already disabled (after a call to
* intel_power_domains_disable()) and paired with intel_power_domains_resume().
*/
void intel_power_domains_suspend(struct drm_i915_private *dev_priv,
void intel_power_domains_suspend(struct drm_i915_private *i915,
enum i915_drm_suspend_mode suspend_mode)
{
struct i915_power_domains *power_domains = &dev_priv->power_domains;
struct i915_power_domains *power_domains = &i915->power_domains;
intel_wakeref_t wakeref __maybe_unused =
fetch_and_zero(&power_domains->wakeref);

intel_display_power_put_unchecked(dev_priv, POWER_DOMAIN_INIT);
intel_display_power_put(i915, POWER_DOMAIN_INIT, wakeref);

/*
* In case of suspend-to-idle (aka S0ix) on a DMC platform without DC9
Expand All @@ -4132,10 +4146,10 @@ void intel_power_domains_suspend(struct drm_i915_private *dev_priv,
* resources as required and also enable deeper system power states
* that would be blocked if the firmware was inactive.
*/
if (!(dev_priv->csr.allowed_dc_mask & DC_STATE_EN_DC9) &&
if (!(i915->csr.allowed_dc_mask & DC_STATE_EN_DC9) &&
suspend_mode == I915_DRM_SUSPEND_IDLE &&
dev_priv->csr.dmc_payload != NULL) {
intel_power_domains_verify_state(dev_priv);
i915->csr.dmc_payload) {
intel_power_domains_verify_state(i915);
return;
}

Expand All @@ -4144,54 +4158,56 @@ void intel_power_domains_suspend(struct drm_i915_private *dev_priv,
* power wells if power domains must be deinitialized for suspend.
*/
if (!i915_modparams.disable_power_well) {
intel_display_power_put_unchecked(dev_priv, POWER_DOMAIN_INIT);
intel_power_domains_verify_state(dev_priv);
intel_display_power_put_unchecked(i915, POWER_DOMAIN_INIT);
intel_power_domains_verify_state(i915);
}

if (IS_ICELAKE(dev_priv))
icl_display_core_uninit(dev_priv);
else if (IS_CANNONLAKE(dev_priv))
cnl_display_core_uninit(dev_priv);
else if (IS_GEN9_BC(dev_priv))
skl_display_core_uninit(dev_priv);
else if (IS_GEN9_LP(dev_priv))
bxt_display_core_uninit(dev_priv);
if (IS_ICELAKE(i915))
icl_display_core_uninit(i915);
else if (IS_CANNONLAKE(i915))
cnl_display_core_uninit(i915);
else if (IS_GEN9_BC(i915))
skl_display_core_uninit(i915);
else if (IS_GEN9_LP(i915))
bxt_display_core_uninit(i915);

power_domains->display_core_suspended = true;
}

/**
* intel_power_domains_resume - resume power domain state
* @dev_priv: i915 device instance
* @i915: i915 device instance
*
* This function resume the hardware power domain state during system resume.
*
* It will return with power domain support disabled (to be enabled later by
* intel_power_domains_enable()) and must be paired with
* intel_power_domains_suspend().
*/
void intel_power_domains_resume(struct drm_i915_private *dev_priv)
void intel_power_domains_resume(struct drm_i915_private *i915)
{
struct i915_power_domains *power_domains = &dev_priv->power_domains;
struct i915_power_domains *power_domains = &i915->power_domains;

if (power_domains->display_core_suspended) {
intel_power_domains_init_hw(dev_priv, true);
intel_power_domains_init_hw(i915, true);
power_domains->display_core_suspended = false;
} else {
intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
WARN_ON(power_domains->wakeref);
power_domains->wakeref =
intel_display_power_get(i915, POWER_DOMAIN_INIT);
}

intel_power_domains_verify_state(dev_priv);
intel_power_domains_verify_state(i915);
}

#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)

static void intel_power_domains_dump_info(struct drm_i915_private *dev_priv)
static void intel_power_domains_dump_info(struct drm_i915_private *i915)
{
struct i915_power_domains *power_domains = &dev_priv->power_domains;
struct i915_power_domains *power_domains = &i915->power_domains;
struct i915_power_well *power_well;

for_each_power_well(dev_priv, power_well) {
for_each_power_well(i915, power_well) {
enum intel_display_power_domain domain;

DRM_DEBUG_DRIVER("%-25s %d\n",
Expand All @@ -4206,30 +4222,29 @@ static void intel_power_domains_dump_info(struct drm_i915_private *dev_priv)

/**
* intel_power_domains_verify_state - verify the HW/SW state for all power wells
* @dev_priv: i915 device instance
* @i915: i915 device instance
*
* Verify if the reference count of each power well matches its HW enabled
* state and the total refcount of the domains it belongs to. This must be
* called after modeset HW state sanitization, which is responsible for
* acquiring reference counts for any power wells in use and disabling the
* ones left on by BIOS but not required by any active output.
*/
static void intel_power_domains_verify_state(struct drm_i915_private *dev_priv)
static void intel_power_domains_verify_state(struct drm_i915_private *i915)
{
struct i915_power_domains *power_domains = &dev_priv->power_domains;
struct i915_power_domains *power_domains = &i915->power_domains;
struct i915_power_well *power_well;
bool dump_domain_info;

mutex_lock(&power_domains->lock);

dump_domain_info = false;
for_each_power_well(dev_priv, power_well) {
for_each_power_well(i915, power_well) {
enum intel_display_power_domain domain;
int domains_count;
bool enabled;

enabled = power_well->desc->ops->is_enabled(dev_priv,
power_well);
enabled = power_well->desc->ops->is_enabled(i915, power_well);
if ((power_well->count || power_well->desc->always_on) !=
enabled)
DRM_ERROR("power well %s state mismatch (refcount %d/enabled %d)",
Expand All @@ -4253,7 +4268,7 @@ static void intel_power_domains_verify_state(struct drm_i915_private *dev_priv)
static bool dumped;

if (!dumped) {
intel_power_domains_dump_info(dev_priv);
intel_power_domains_dump_info(i915);
dumped = true;
}
}
Expand All @@ -4263,7 +4278,7 @@ static void intel_power_domains_verify_state(struct drm_i915_private *dev_priv)

#else

static void intel_power_domains_verify_state(struct drm_i915_private *dev_priv)
static void intel_power_domains_verify_state(struct drm_i915_private *i915)
{
}

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