ACPI / PM: Split acpi_device_wakeup()

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@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This commit is contained in:
Rafael J. Wysocki 2017-07-21 14:40:49 +02:00
parent baecc470d5
commit 99d8845e75
2 changed files with 82 additions and 45 deletions

View File

@ -682,47 +682,74 @@ static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
}
}
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;
mutex_lock(&acpi_wakeup_lock);
if (wakeup->enable_count > 0)
goto out;
error = acpi_enable_wakeup_device_power(adev, target_state);
if (error)
goto out;
status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
if (ACPI_FAILURE(status)) {
acpi_disable_wakeup_device_power(adev);
error = -EIO;
goto out;
}
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;
if (enable) {
acpi_status res;
int error;
mutex_lock(&acpi_wakeup_lock);
if (adev->wakeup.flags.enabled)
return 0;
if (!wakeup->enable_count)
goto out;
error = acpi_enable_wakeup_device_power(adev, target_state);
if (error)
return error;
acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
acpi_disable_wakeup_device_power(adev);
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);
acpi_disable_wakeup_device_power(adev);
adev->wakeup.flags.enabled = 0;
}
return 0;
wakeup->enable_count--;
out:
mutex_unlock(&acpi_wakeup_lock);
}
/**
@ -744,9 +771,15 @@ int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
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;
}
@ -800,13 +833,15 @@ int acpi_dev_runtime_suspend(struct device *dev)
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;
}
@ -829,7 +864,7 @@ int acpi_dev_runtime_resume(struct device *dev)
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);
@ -884,13 +919,15 @@ int acpi_dev_suspend_late(struct device *dev)
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;
}
@ -913,7 +950,7 @@ int acpi_dev_resume_early(struct device *dev)
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);
@ -1056,7 +1093,7 @@ static void acpi_dev_pm_detach(struct device *dev, bool power_off)
*/
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);
}
}
@ -1100,7 +1137,7 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on)
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;

View File

@ -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 {