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Date: Mon, 26 Nov 2012 08:43:10 +0800
From: Huang Ying <ying.huang@...el.com>
To: "Rafael J. Wysocki" <rjw@...k.pl>
Cc: LKML <linux-kernel@...r.kernel.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Linux PM list <linux-pm@...r.kernel.org>,
ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
Zhang Rui <rui.zhang@...el.com>,
"Svahn, Kai" <kai.svahn@...el.com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
"Lan, Tianyu" <tianyu.lan@...el.com>,
"Zheng, Lv" <lv.zheng@...el.com>, Aaron Lu <aaron.lu@...el.com>,
Grant Likely <grant.likely@...retlab.ca>
Subject: Re: [PATCH 1/2] ACPI / PM: Allow attach/detach routines to change
device power states
On Sun, 2012-11-25 at 15:55 +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
>
> Make it possible to ask the routines used for adding/removing devices
> to/from the general ACPI PM domain, acpi_dev_pm_attach() and
> acpi_dev_pm_detach(), respectively, to change the power states of
> devices so that they are put into the full-power state automatically
> by acpi_dev_pm_attach() and into the lowest-power state available
> automatically by acpi_dev_pm_detach().
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
> drivers/acpi/device_pm.c | 28 ++++++++++++++++++++++++----
> include/linux/acpi.h | 11 +++++++----
> 2 files changed, 31 insertions(+), 8 deletions(-)
>
> Index: linux/drivers/acpi/device_pm.c
> ===================================================================
> --- linux.orig/drivers/acpi/device_pm.c
> +++ linux/drivers/acpi/device_pm.c
> @@ -599,10 +599,12 @@ static struct dev_pm_domain acpi_general
> /**
> * acpi_dev_pm_attach - Prepare device for ACPI power management.
> * @dev: Device to prepare.
> + * @power_on: Whether or not to power on the device.
> *
> * If @dev has a valid ACPI handle that has a valid struct acpi_device object
> * attached to it, install a wakeup notification handler for the device and
> - * add it to the general ACPI PM domain.
> + * add it to the general ACPI PM domain. If @power_on is set, the device will
> + * be put into the ACPI D0 state before the function returns.
> *
> * This assumes that the @dev's bus type uses generic power management callbacks
> * (or doesn't use any power management callbacks at all).
> @@ -610,7 +612,7 @@ static struct dev_pm_domain acpi_general
> * Callers must ensure proper synchronization of this function with power
> * management callbacks.
> */
> -int acpi_dev_pm_attach(struct device *dev)
> +int acpi_dev_pm_attach(struct device *dev, bool power_on)
> {
> struct acpi_device *adev = acpi_dev_pm_get_node(dev);
>
> @@ -622,6 +624,10 @@ int acpi_dev_pm_attach(struct device *de
>
> acpi_add_pm_notifier(adev, acpi_wakeup_device, dev);
> dev->pm_domain = &acpi_general_pm_domain;
> + if (power_on) {
> + acpi_dev_pm_full_power(adev);
> + __acpi_device_run_wake(adev, false);
> + }
> return 0;
> }
> EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
> @@ -629,20 +635,34 @@ EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
> /**
> * acpi_dev_pm_detach - Remove ACPI power management from the device.
> * @dev: Device to take care of.
> + * @power_off: Whether or not to try to remove power from the device.
> *
> * Remove the device from the general ACPI PM domain and remove its wakeup
> - * notifier.
> + * notifier. If @power_off is set, additionally remove power from the device if
> + * possible.
> *
> * Callers must ensure proper synchronization of this function with power
> * management callbacks.
> */
> -void acpi_dev_pm_detach(struct device *dev)
> +void acpi_dev_pm_detach(struct device *dev, bool power_off)
> {
> struct acpi_device *adev = acpi_dev_pm_get_node(dev);
>
> if (adev && dev->pm_domain == &acpi_general_pm_domain) {
> dev->pm_domain = NULL;
> acpi_remove_pm_notifier(adev, acpi_wakeup_device);
> + if (power_off) {
> + /*
> + * If the device's PM QoS resume latency limit or flags
> + * have been exposed to user space, they have to be
> + * hidden at this point, so that they don't affect the
> + * choice of the low-power state to put the device into.
> + */
> + dev_pm_qos_hide_latency_limit(dev);
> + dev_pm_qos_hide_flags(dev);
NO_POWER_OFF flag is ignored here. Is it possible for some device (or
corresponding ACPI method) has broken D3cold implementation, so that the
user need a way to disable it?
Best Regards,
Huang Ying
> + __acpi_device_run_wake(adev, false);
> + acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
> + }
> }
> }
> EXPORT_SYMBOL_GPL(acpi_dev_pm_detach);
> Index: linux/include/linux/acpi.h
> ===================================================================
> --- linux.orig/include/linux/acpi.h
> +++ linux/include/linux/acpi.h
> @@ -510,11 +510,14 @@ static inline int acpi_subsys_resume_ear
> #endif
>
> #if defined(CONFIG_ACPI) && defined(CONFIG_PM)
> -int acpi_dev_pm_attach(struct device *dev);
> -int acpi_dev_pm_detach(struct device *dev);
> +int acpi_dev_pm_attach(struct device *dev, bool power_on);
> +int acpi_dev_pm_detach(struct device *dev, bool power_off);
> #else
> -static inline int acpi_dev_pm_attach(struct device *dev) { return -ENODEV; }
> -static inline void acpi_dev_pm_detach(struct device *dev) {}
> +static inline int acpi_dev_pm_attach(struct device *dev, bool power_on)
> +{
> + return -ENODEV;
> +}
> +static inline void acpi_dev_pm_detach(struct device *dev, bool power_off) {}
> #endif
>
> #ifdef CONFIG_ACPI
>
--
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