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Date: Fri, 21 Jul 2017 14:40:49 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PCI <linux-pci@...r.kernel.org>
Cc: Linux ACPI <linux-acpi@...r.kernel.org>,
Linux PM <linux-pm@...r.kernel.org>,
LKML <linux-kernel@...r.kernel.org>,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
Bjorn Helgaas <bhelgaas@...gle.com>
Subject: [PATCH 2/3] ACPI / PM: Split acpi_device_wakeup()
From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
To prepare for a subsequent change and make the code somewhat easier
to follow, do the following in the ACPI device wakeup handling code:
* Replace wakeup.flags.enabled under struct acpi_device with
wakeup.enable_count as that will be necessary going forward.
For now, wakeup.enable_count is not allowed to grow beyond 1,
so the current behavior is retained.
* Split acpi_device_wakeup() into acpi_device_wakeup_enable()
and acpi_device_wakeup_disable() and modify the callers of
it accordingly.
* Introduce a new acpi_wakeup_lock mutex to protect the wakeup
enabling/disabling code from races in case it is executed
more than once in parallel for the same device (which may
happen for bridges theoretically).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
drivers/acpi/device_pm.c | 121 ++++++++++++++++++++++++++++++-----------------
include/acpi/acpi_bus.h | 2
2 files changed, 80 insertions(+), 43 deletions(-)
Index: linux-pm/drivers/acpi/device_pm.c
===================================================================
--- linux-pm.orig/drivers/acpi/device_pm.c
+++ linux-pm/drivers/acpi/device_pm.c
@@ -680,47 +680,74 @@ static void acpi_pm_notify_work_func(str
}
}
+static DEFINE_MUTEX(acpi_wakeup_lock);
+
/**
- * acpi_device_wakeup - Enable/disable wakeup functionality for device.
- * @adev: ACPI device to enable/disable wakeup functionality for.
+ * acpi_device_wakeup_enable - Enable wakeup functionality for device.
+ * @adev: ACPI device to enable wakeup functionality for.
* @target_state: State the system is transitioning into.
- * @enable: Whether to enable or disable the wakeup functionality.
*
- * Enable/disable the GPE associated with @adev so that it can generate
- * wakeup signals for the device in response to external (remote) events and
- * enable/disable device wakeup power.
+ * Enable the GPE associated with @adev so that it can generate wakeup signals
+ * for the device in response to external (remote) events and enable wakeup
+ * power for it.
*
* Callers must ensure that @adev is a valid ACPI device node before executing
* this function.
*/
-static int acpi_device_wakeup(struct acpi_device *adev, u32 target_state,
- bool enable)
+static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
{
struct acpi_device_wakeup *wakeup = &adev->wakeup;
+ acpi_status status;
+ int error = 0;
- if (enable) {
- acpi_status res;
- int error;
+ mutex_lock(&acpi_wakeup_lock);
- if (adev->wakeup.flags.enabled)
- return 0;
+ if (wakeup->enable_count > 0)
+ goto out;
- error = acpi_enable_wakeup_device_power(adev, target_state);
- if (error)
- return error;
+ error = acpi_enable_wakeup_device_power(adev, target_state);
+ if (error)
+ goto out;
- res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
- if (ACPI_FAILURE(res)) {
- acpi_disable_wakeup_device_power(adev);
- return -EIO;
- }
- adev->wakeup.flags.enabled = 1;
- } else if (adev->wakeup.flags.enabled) {
- acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
+ status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
+ if (ACPI_FAILURE(status)) {
acpi_disable_wakeup_device_power(adev);
- adev->wakeup.flags.enabled = 0;
+ error = -EIO;
+ goto out;
}
- return 0;
+
+ wakeup->enable_count++;
+
+out:
+ mutex_unlock(&acpi_wakeup_lock);
+ return error;
+}
+
+/**
+ * acpi_device_wakeup_disable - Disable wakeup functionality for device.
+ * @adev: ACPI device to disable wakeup functionality for.
+ *
+ * Disable the GPE associated with @adev and disable wakeup power for it.
+ *
+ * Callers must ensure that @adev is a valid ACPI device node before executing
+ * this function.
+ */
+static void acpi_device_wakeup_disable(struct acpi_device *adev)
+{
+ struct acpi_device_wakeup *wakeup = &adev->wakeup;
+
+ mutex_lock(&acpi_wakeup_lock);
+
+ if (!wakeup->enable_count)
+ goto out;
+
+ acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
+ acpi_disable_wakeup_device_power(adev);
+
+ wakeup->enable_count--;
+
+out:
+ mutex_unlock(&acpi_wakeup_lock);
}
/**
@@ -742,9 +769,15 @@ int acpi_pm_set_device_wakeup(struct dev
if (!acpi_device_can_wakeup(adev))
return -EINVAL;
- error = acpi_device_wakeup(adev, acpi_target_system_state(), enable);
+ if (!enable) {
+ acpi_device_wakeup_disable(adev);
+ dev_dbg(dev, "Wakeup disabled by ACPI\n");
+ return 0;
+ }
+
+ error = acpi_device_wakeup_enable(adev, acpi_target_system_state());
if (!error)
- dev_dbg(dev, "Wakeup %s by ACPI\n", enable ? "enabled" : "disabled");
+ dev_dbg(dev, "Wakeup enabled by ACPI\n");
return error;
}
@@ -798,13 +831,15 @@ int acpi_dev_runtime_suspend(struct devi
remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) >
PM_QOS_FLAGS_NONE;
- error = acpi_device_wakeup(adev, ACPI_STATE_S0, remote_wakeup);
- if (remote_wakeup && error)
- return -EAGAIN;
+ if (remote_wakeup) {
+ error = acpi_device_wakeup_enable(adev, ACPI_STATE_S0);
+ if (error)
+ return -EAGAIN;
+ }
error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
- if (error)
- acpi_device_wakeup(adev, ACPI_STATE_S0, false);
+ if (error && remote_wakeup)
+ acpi_device_wakeup_disable(adev);
return error;
}
@@ -827,7 +862,7 @@ int acpi_dev_runtime_resume(struct devic
return 0;
error = acpi_dev_pm_full_power(adev);
- acpi_device_wakeup(adev, ACPI_STATE_S0, false);
+ acpi_device_wakeup_disable(adev);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume);
@@ -882,13 +917,15 @@ int acpi_dev_suspend_late(struct device
target_state = acpi_target_system_state();
wakeup = device_may_wakeup(dev) && acpi_device_can_wakeup(adev);
- error = acpi_device_wakeup(adev, target_state, wakeup);
- if (wakeup && error)
- return error;
+ if (wakeup) {
+ error = acpi_device_wakeup_enable(adev, target_state);
+ if (error)
+ return error;
+ }
error = acpi_dev_pm_low_power(dev, adev, target_state);
- if (error)
- acpi_device_wakeup(adev, ACPI_STATE_UNKNOWN, false);
+ if (error && wakeup)
+ acpi_device_wakeup_disable(adev);
return error;
}
@@ -911,7 +948,7 @@ int acpi_dev_resume_early(struct device
return 0;
error = acpi_dev_pm_full_power(adev);
- acpi_device_wakeup(adev, ACPI_STATE_UNKNOWN, false);
+ acpi_device_wakeup_disable(adev);
return error;
}
EXPORT_SYMBOL_GPL(acpi_dev_resume_early);
@@ -1054,7 +1091,7 @@ static void acpi_dev_pm_detach(struct de
*/
dev_pm_qos_hide_latency_limit(dev);
dev_pm_qos_hide_flags(dev);
- acpi_device_wakeup(adev, ACPI_STATE_S0, false);
+ acpi_device_wakeup_disable(adev);
acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
}
}
@@ -1098,7 +1135,7 @@ int acpi_dev_pm_attach(struct device *de
dev_pm_domain_set(dev, &acpi_general_pm_domain);
if (power_on) {
acpi_dev_pm_full_power(adev);
- acpi_device_wakeup(adev, ACPI_STATE_S0, false);
+ acpi_device_wakeup_disable(adev);
}
dev->pm_domain->detach = acpi_dev_pm_detach;
Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -316,7 +316,6 @@ struct acpi_device_perf {
struct acpi_device_wakeup_flags {
u8 valid:1; /* Can successfully enable wakeup? */
u8 notifier_present:1; /* Wake-up notify handler has been installed */
- u8 enabled:1; /* Enabled for wakeup */
};
struct acpi_device_wakeup_context {
@@ -333,6 +332,7 @@ struct acpi_device_wakeup {
struct acpi_device_wakeup_context context;
struct wakeup_source *ws;
int prepare_count;
+ int enable_count;
};
struct acpi_device_physical_node {
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