From 99d8845e756cb91e2865f430401d084cd6a8ccc9 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 21 Jul 2017 14:40:49 +0200 Subject: 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 Reviewed-by: Mika Westerberg --- drivers/acpi/device_pm.c | 121 +++++++++++++++++++++++++++++++---------------- 1 file changed, 79 insertions(+), 42 deletions(-) (limited to 'drivers/acpi/device_pm.c') diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 2ed6935d4483..4cd4bdab053d 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -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; - 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); } /** @@ -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; -- cgit v1.2.3