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Date: Mon, 19 Mar 2012 09:32:07 +0800
From: Lin Ming <ming.m.lin@...el.com>
To: Zhang Rui <rui.zhang@...el.com>, Jeff Garzik <jgarzik@...ox.com>,
Alan Stern <stern@...land.harvard.edu>,
"Rafael J. Wysocki" <rjw@...k.pl>, Tejun Heo <tj@...nel.org>,
Aaron Lu <aaron.lu@....com>
Cc: linux-kernel@...r.kernel.org, linux-ide@...r.kernel.org,
linux-scsi@...r.kernel.org, linux-pm@...r.kernel.org,
linux-acpi <linux-acpi@...r.kernel.org>
Subject: Re: [RFC PATCH v2 2/8] ACPI: Add interface to register/unregister
device to/from power resources
On Thu, Mar 1, 2012 at 5:02 PM, Lin Ming <ming.m.lin@...el.com> wrote:
> Devices may share same list of power resources in _PR0, for example
>
> Device(Dev0)
> {
> Name (_PR0, Package (0x01)
> {
> P0PR,
> P1PR
> })
> }
>
> Device(Dev1)
> {
> Name (_PR0, Package (0x01)
> {
> P0PR,
> P1PR
> }
> }
>
> Assume Dev0 and Dev1 were runtime suspended.
> Then Dev0 is resumed first and it goes into D0 state.
> But Dev1 is left in D0_Uninitialised state.
>
> This is wrong. In this case, Dev1 must be resumed too.
>
> In order to hand this case, each power resource maintains a list of
> devices which relies on it.
>
> When power resource is ON, it will check if the devices on its list
> can be resumed. The device can only be resumed when all the power
> resouces of its _PR0 are ON.
>
> Signed-off-by: Lin Ming <ming.m.lin@...el.com>
Hi Rafael,
This version addressed your comment at:
https://lkml.org/lkml/2012/2/13/355
Now we support all combinations of device/power resource.
Do you like it?
Thanks,
Lin Ming
> ---
> drivers/acpi/power.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++
> include/acpi/acpi_bus.h | 2 +
> 2 files changed, 164 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
> index 0d681fb..7049a7d 100644
> --- a/drivers/acpi/power.c
> +++ b/drivers/acpi/power.c
> @@ -40,9 +40,11 @@
> #include <linux/init.h>
> #include <linux/types.h>
> #include <linux/slab.h>
> +#include <linux/pm_runtime.h>
> #include <acpi/acpi_bus.h>
> #include <acpi/acpi_drivers.h>
> #include "sleep.h"
> +#include "internal.h"
>
> #define PREFIX "ACPI: "
>
> @@ -77,6 +79,20 @@ static struct acpi_driver acpi_power_driver = {
> },
> };
>
> +/*
> + * A power managed device
> + * A device may rely on multiple power resources.
> + * */
> +struct acpi_power_managed_device {
> + struct device *dev; /* The physical device */
> + acpi_handle *handle;
> +};
> +
> +struct acpi_power_resource_device {
> + struct acpi_power_managed_device *device;
> + struct acpi_power_resource_device *next;
> +};
> +
> struct acpi_power_resource {
> struct acpi_device * device;
> acpi_bus_id name;
> @@ -84,6 +100,9 @@ struct acpi_power_resource {
> u32 order;
> unsigned int ref_count;
> struct mutex resource_lock;
> +
> + /* List of devices relying on this power resource */
> + struct acpi_power_resource_device *devices;
> };
>
> static struct list_head acpi_power_resource_list;
> @@ -183,8 +202,26 @@ static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
> return 0;
> }
>
> +/* Resume the device when all power resources in _PR0 are on */
> +static void acpi_power_on_device(struct acpi_power_managed_device *device)
> +{
> + struct acpi_device *acpi_dev;
> + acpi_handle handle = device->handle;
> + int state;
> +
> + if (acpi_bus_get_device(handle, &acpi_dev))
> + return;
> +
> + if(acpi_power_get_inferred_state(acpi_dev, &state))
> + return;
> +
> + if (state == ACPI_STATE_D0 && pm_runtime_suspended(device->dev))
> + pm_request_resume(device->dev);
> +}
> +
> static int __acpi_power_on(struct acpi_power_resource *resource)
> {
> + struct acpi_power_resource_device *device_list = resource->devices;
> acpi_status status = AE_OK;
>
> status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
> @@ -197,6 +234,12 @@ static int __acpi_power_on(struct acpi_power_resource *resource)
> ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
> resource->name));
>
> + while (device_list) {
> + acpi_power_on_device(device_list->device);
> +
> + device_list = device_list->next;
> + }
> +
> return 0;
> }
>
> @@ -299,6 +342,125 @@ static int acpi_power_on_list(struct acpi_handle_list *list)
> return result;
> }
>
> +static void __acpi_power_resource_unregister_device(struct device *dev,
> + acpi_handle res_handle)
> +{
> + struct acpi_power_resource *resource = NULL;
> + struct acpi_power_resource_device *prev, *curr;
> +
> + if (acpi_power_get_context(res_handle, &resource))
> + return;
> +
> + mutex_lock(&resource->resource_lock);
> + prev = NULL;
> + curr = resource->devices;
> + while (curr) {
> + if (curr->device->dev == dev) {
> + if (!prev)
> + resource->devices = curr->next;
> + else
> + prev->next = curr->next;
> +
> + kfree(curr);
> + break;
> + }
> +
> + prev = curr;
> + curr = curr->next;
> + }
> + mutex_unlock(&resource->resource_lock);
> +}
> +
> +/* Unlink dev from all power resources in _PR0 */
> +void acpi_power_resource_unregister_device(struct device *dev, acpi_handle handle)
> +{
> + struct acpi_device *acpi_dev;
> + struct acpi_handle_list *list;
> + int i;
> +
> + if (!dev || !handle)
> + return;
> +
> + if (acpi_bus_get_device(handle, &acpi_dev))
> + return;
> +
> + list = &acpi_dev->power.states[ACPI_STATE_D0].resources;
> +
> + for (i = 0; i < list->count; i++)
> + __acpi_power_resource_unregister_device(dev,
> + list->handles[i]);
> +}
> +
> +static int __acpi_power_resource_register_device(
> + struct acpi_power_managed_device *powered_device, acpi_handle handle)
> +{
> + struct acpi_power_resource *resource = NULL;
> + struct acpi_power_resource_device *power_resource_device;
> + int result;
> +
> + result = acpi_power_get_context(handle, &resource);
> + if (result)
> + return result;
> +
> + power_resource_device = kzalloc(
> + sizeof(*power_resource_device), GFP_KERNEL);
> + if (!power_resource_device)
> + return -ENOMEM;
> +
> + power_resource_device->device = powered_device;
> +
> + mutex_lock(&resource->resource_lock);
> + power_resource_device->next = resource->devices;
> + resource->devices = power_resource_device;
> + mutex_unlock(&resource->resource_lock);
> +
> + return 0;
> +}
> +
> +/* Link dev to all power resources in _PR0 */
> +int acpi_power_resource_register_device(struct device *dev, acpi_handle handle)
> +{
> + struct acpi_device *acpi_dev;
> + struct acpi_handle_list *list;
> + struct acpi_power_managed_device *powered_device;
> + int i, ret;
> +
> + if (!dev || !handle)
> + return -ENODEV;
> +
> + ret = acpi_bus_get_device(handle, &acpi_dev);
> + if (ret)
> + goto no_power_resource;
> +
> + if (!acpi_dev->power.flags.power_resources)
> + goto no_power_resource;
> +
> + powered_device = kzalloc(sizeof(*powered_device), GFP_KERNEL);
> + if (!powered_device)
> + return -ENOMEM;
> +
> + powered_device->dev = dev;
> + powered_device->handle = handle;
> +
> + list = &acpi_dev->power.states[ACPI_STATE_D0].resources;
> +
> + for (i = 0; i < list->count; i++) {
> + ret = __acpi_power_resource_register_device(powered_device,
> + list->handles[i]);
> +
> + if (ret) {
> + acpi_power_resource_unregister_device(dev, handle);
> + break;
> + }
> + }
> +
> + return ret;
> +
> +no_power_resource:
> + printk(KERN_WARNING PREFIX "Invalid Power Resource to register!");
> + return -ENODEV;
> +}
> +
> /**
> * acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
> * ACPI 3.0) _PSW (Power State Wake)
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 6cd5b64..e168fff 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -323,6 +323,8 @@ int acpi_bus_set_power(acpi_handle handle, int state);
> int acpi_bus_update_power(acpi_handle handle, int *state_p);
> bool acpi_bus_power_manageable(acpi_handle handle);
> bool acpi_bus_can_wakeup(acpi_handle handle);
> +int acpi_power_resource_register_device(struct device *dev, acpi_handle handle);
> +void acpi_power_resource_unregister_device(struct device *dev, acpi_handle handle);
> #ifdef CONFIG_ACPI_PROC_EVENT
> int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data);
> int acpi_bus_generate_proc_event4(const char *class, const char *bid, u8 type, int data);
> --
> 1.7.2.5
>
> --
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