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linux-stable/include/linux/pm_domain.h
Ulf Hansson 67732cd343 PM / Domains: Fix initial default state of the need_restore flag 
The initial state of the device's need_restore flag should'nt depend on
the current state of the PM domain. For example it should be perfectly
valid to attach an inactive device to a powered PM domain.

The pm_genpd_dev_need_restore() API allow us to update the need_restore
flag to somewhat cope with such scenarios. Typically that should have
been done from drivers/buses ->probe() since it's those that put the
requirements on the value of the need_restore flag.

Until recently, the Exynos SOCs were the only user of the
pm_genpd_dev_need_restore() API, though invoking it from a centralized
location while adding devices to their PM domains.

Due to that Exynos now have swithed to the generic OF-based PM domain
look-up, it's no longer possible to invoke the API from a centralized
location. The reason is because devices are now added to their PM
domains during the probe sequence.

Commit "ARM: exynos: Move to generic PM domain DT bindings"
did the switch for Exynos to the generic OF-based PM domain look-up,
but it also removed the call to pm_genpd_dev_need_restore(). This
caused a regression for some of the Exynos drivers.

To handle things more properly in the generic PM domain, let's change
the default initial value of the need_restore flag to reflect that the
state is unknown. As soon as some of the runtime PM callbacks gets
invoked, update the initial value accordingly.

Moreover, since the generic PM domain is verifying that all devices
are both runtime PM enabled and suspended, using pm_runtime_suspended()
while pm_genpd_poweroff() is invoked from the scheduled work, we can be
sure of that the PM domain won't be powering off while having active
devices.

Do note that, the generic PM domain can still only know about active
devices which has been activated through invoking its runtime PM resume
callback. In other words, buses/drivers using pm_runtime_set_active()
during ->probe() will still suffer from a race condition, potentially
probing a device without having its PM domain being powered. That issue
will have to be solved using a different approach.

This a log from the boot regression for Exynos5, which is being fixed in
this patch.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 308 at ../drivers/clk/clk.c:851 clk_disable+0x24/0x30()
Modules linked in:
CPU: 0 PID: 308 Comm: kworker/0:1 Not tainted 3.18.0-rc3-00569-gbd9449f-dirty #10
Workqueue: pm pm_runtime_work
[<c0013c64>] (unwind_backtrace) from [<c0010dec>] (show_stack+0x10/0x14)
[<c0010dec>] (show_stack) from [<c03ee4cc>] (dump_stack+0x70/0xbc)
[<c03ee4cc>] (dump_stack) from [<c0020d34>] (warn_slowpath_common+0x64/0x88)
[<c0020d34>] (warn_slowpath_common) from [<c0020d74>] (warn_slowpath_null+0x1c/0x24)
[<c0020d74>] (warn_slowpath_null) from [<c03107b0>] (clk_disable+0x24/0x30)
[<c03107b0>] (clk_disable) from [<c02cc834>] (gsc_runtime_suspend+0x128/0x160)
[<c02cc834>] (gsc_runtime_suspend) from [<c0249024>] (pm_generic_runtime_suspend+0x2c/0x38)
[<c0249024>] (pm_generic_runtime_suspend) from [<c024f44c>] (pm_genpd_default_save_state+0x2c/0x8c)
[<c024f44c>] (pm_genpd_default_save_state) from [<c024ff2c>] (pm_genpd_poweroff+0x224/0x3ec)
[<c024ff2c>] (pm_genpd_poweroff) from [<c02501b4>] (pm_genpd_runtime_suspend+0x9c/0xcc)
[<c02501b4>] (pm_genpd_runtime_suspend) from [<c024a4f8>] (__rpm_callback+0x2c/0x60)
[<c024a4f8>] (__rpm_callback) from [<c024a54c>] (rpm_callback+0x20/0x74)
[<c024a54c>] (rpm_callback) from [<c024a930>] (rpm_suspend+0xd4/0x43c)
[<c024a930>] (rpm_suspend) from [<c024bbcc>] (pm_runtime_work+0x80/0x90)
[<c024bbcc>] (pm_runtime_work) from [<c0032a9c>] (process_one_work+0x12c/0x314)
[<c0032a9c>] (process_one_work) from [<c0032cf4>] (worker_thread+0x3c/0x4b0)
[<c0032cf4>] (worker_thread) from [<c003747c>] (kthread+0xcc/0xe8)
[<c003747c>] (kthread) from [<c000e738>] (ret_from_fork+0x14/0x3c)
---[ end trace 40cd58bcd6988f12 ]---

Fixes: a4a8c2c496 (ARM: exynos: Move to generic PM domain DT bindings)
Reported-and-tested0by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-11 22:28:44 +01:00

317 lines
9.5 KiB
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/*
* pm_domain.h - Definitions and headers related to device power domains.
*
* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
*
* This file is released under the GPLv2.
*/
#ifndef _LINUX_PM_DOMAIN_H
#define _LINUX_PM_DOMAIN_H
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/notifier.h>
#include <linux/cpuidle.h>
enum gpd_status {
GPD_STATE_ACTIVE = 0, /* PM domain is active */
GPD_STATE_WAIT_MASTER, /* PM domain's master is being waited for */
GPD_STATE_BUSY, /* Something is happening to the PM domain */
GPD_STATE_REPEAT, /* Power off in progress, to be repeated */
GPD_STATE_POWER_OFF, /* PM domain is off */
};
struct dev_power_governor {
bool (*power_down_ok)(struct dev_pm_domain *domain);
bool (*stop_ok)(struct device *dev);
};
struct gpd_dev_ops {
int (*start)(struct device *dev);
int (*stop)(struct device *dev);
int (*save_state)(struct device *dev);
int (*restore_state)(struct device *dev);
bool (*active_wakeup)(struct device *dev);
};
struct gpd_cpuidle_data {
unsigned int saved_exit_latency;
struct cpuidle_state *idle_state;
};
struct generic_pm_domain {
struct dev_pm_domain domain; /* PM domain operations */
struct list_head gpd_list_node; /* Node in the global PM domains list */
struct list_head master_links; /* Links with PM domain as a master */
struct list_head slave_links; /* Links with PM domain as a slave */
struct list_head dev_list; /* List of devices */
struct mutex lock;
struct dev_power_governor *gov;
struct work_struct power_off_work;
const char *name;
unsigned int in_progress; /* Number of devices being suspended now */
atomic_t sd_count; /* Number of subdomains with power "on" */
enum gpd_status status; /* Current state of the domain */
wait_queue_head_t status_wait_queue;
struct task_struct *poweroff_task; /* Powering off task */
unsigned int resume_count; /* Number of devices being resumed */
unsigned int device_count; /* Number of devices */
unsigned int suspended_count; /* System suspend device counter */
unsigned int prepared_count; /* Suspend counter of prepared devices */
bool suspend_power_off; /* Power status before system suspend */
int (*power_off)(struct generic_pm_domain *domain);
s64 power_off_latency_ns;
int (*power_on)(struct generic_pm_domain *domain);
s64 power_on_latency_ns;
struct gpd_dev_ops dev_ops;
s64 max_off_time_ns; /* Maximum allowed "suspended" time. */
bool max_off_time_changed;
bool cached_power_down_ok;
struct gpd_cpuidle_data *cpuidle_data;
int (*attach_dev)(struct generic_pm_domain *domain,
struct device *dev);
void (*detach_dev)(struct generic_pm_domain *domain,
struct device *dev);
};
static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd)
{
return container_of(pd, struct generic_pm_domain, domain);
}
struct gpd_link {
struct generic_pm_domain *master;
struct list_head master_node;
struct generic_pm_domain *slave;
struct list_head slave_node;
};
struct gpd_timing_data {
s64 stop_latency_ns;
s64 start_latency_ns;
s64 save_state_latency_ns;
s64 restore_state_latency_ns;
s64 effective_constraint_ns;
bool constraint_changed;
bool cached_stop_ok;
};
struct generic_pm_domain_data {
struct pm_domain_data base;
struct gpd_timing_data td;
struct notifier_block nb;
struct mutex lock;
unsigned int refcount;
int need_restore;
};
#ifdef CONFIG_PM_GENERIC_DOMAINS
static inline struct generic_pm_domain_data *to_gpd_data(struct pm_domain_data *pdd)
{
return container_of(pdd, struct generic_pm_domain_data, base);
}
static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
{
return to_gpd_data(dev->power.subsys_data->domain_data);
}
extern struct generic_pm_domain *dev_to_genpd(struct device *dev);
extern int __pm_genpd_add_device(struct generic_pm_domain *genpd,
struct device *dev,
struct gpd_timing_data *td);
extern int __pm_genpd_name_add_device(const char *domain_name,
struct device *dev,
struct gpd_timing_data *td);
extern int pm_genpd_remove_device(struct generic_pm_domain *genpd,
struct device *dev);
extern void pm_genpd_dev_need_restore(struct device *dev, bool val);
extern int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *new_subdomain);
extern int pm_genpd_add_subdomain_names(const char *master_name,
const char *subdomain_name);
extern int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *target);
extern int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state);
extern int pm_genpd_name_attach_cpuidle(const char *name, int state);
extern int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd);
extern int pm_genpd_name_detach_cpuidle(const char *name);
extern void pm_genpd_init(struct generic_pm_domain *genpd,
struct dev_power_governor *gov, bool is_off);
extern int pm_genpd_poweron(struct generic_pm_domain *genpd);
extern int pm_genpd_name_poweron(const char *domain_name);
extern struct dev_power_governor simple_qos_governor;
extern struct dev_power_governor pm_domain_always_on_gov;
#else
static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
{
return ERR_PTR(-ENOSYS);
}
static inline struct generic_pm_domain *dev_to_genpd(struct device *dev)
{
return ERR_PTR(-ENOSYS);
}
static inline int __pm_genpd_add_device(struct generic_pm_domain *genpd,
struct device *dev,
struct gpd_timing_data *td)
{
return -ENOSYS;
}
static inline int __pm_genpd_name_add_device(const char *domain_name,
struct device *dev,
struct gpd_timing_data *td)
{
return -ENOSYS;
}
static inline int pm_genpd_remove_device(struct generic_pm_domain *genpd,
struct device *dev)
{
return -ENOSYS;
}
static inline void pm_genpd_dev_need_restore(struct device *dev, bool val) {}
static inline int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *new_sd)
{
return -ENOSYS;
}
static inline int pm_genpd_add_subdomain_names(const char *master_name,
const char *subdomain_name)
{
return -ENOSYS;
}
static inline int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *target)
{
return -ENOSYS;
}
static inline int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int st)
{
return -ENOSYS;
}
static inline int pm_genpd_name_attach_cpuidle(const char *name, int state)
{
return -ENOSYS;
}
static inline int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd)
{
return -ENOSYS;
}
static inline int pm_genpd_name_detach_cpuidle(const char *name)
{
return -ENOSYS;
}
static inline void pm_genpd_init(struct generic_pm_domain *genpd,
struct dev_power_governor *gov, bool is_off)
{
}
static inline int pm_genpd_poweron(struct generic_pm_domain *genpd)
{
return -ENOSYS;
}
static inline int pm_genpd_name_poweron(const char *domain_name)
{
return -ENOSYS;
}
#define simple_qos_governor NULL
#define pm_domain_always_on_gov NULL
#endif
static inline int pm_genpd_add_device(struct generic_pm_domain *genpd,
struct device *dev)
{
return __pm_genpd_add_device(genpd, dev, NULL);
}
static inline int pm_genpd_name_add_device(const char *domain_name,
struct device *dev)
{
return __pm_genpd_name_add_device(domain_name, dev, NULL);
}
#ifdef CONFIG_PM_GENERIC_DOMAINS_RUNTIME
extern void pm_genpd_poweroff_unused(void);
#else
static inline void pm_genpd_poweroff_unused(void) {}
#endif
#ifdef CONFIG_PM_GENERIC_DOMAINS_SLEEP
extern void pm_genpd_syscore_poweroff(struct device *dev);
extern void pm_genpd_syscore_poweron(struct device *dev);
#else
static inline void pm_genpd_syscore_poweroff(struct device *dev) {}
static inline void pm_genpd_syscore_poweron(struct device *dev) {}
#endif
/* OF PM domain providers */
struct of_device_id;
struct genpd_onecell_data {
struct generic_pm_domain **domains;
unsigned int num_domains;
};
typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args,
void *data);
#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
void *data);
void of_genpd_del_provider(struct device_node *np);
struct generic_pm_domain *__of_genpd_xlate_simple(
struct of_phandle_args *genpdspec,
void *data);
struct generic_pm_domain *__of_genpd_xlate_onecell(
struct of_phandle_args *genpdspec,
void *data);
int genpd_dev_pm_attach(struct device *dev);
#else /* !CONFIG_PM_GENERIC_DOMAINS_OF */
static inline int __of_genpd_add_provider(struct device_node *np,
genpd_xlate_t xlate, void *data)
{
return 0;
}
static inline void of_genpd_del_provider(struct device_node *np) {}
#define __of_genpd_xlate_simple NULL
#define __of_genpd_xlate_onecell NULL
static inline int genpd_dev_pm_attach(struct device *dev)
{
return -ENODEV;
}
#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
static inline int of_genpd_add_provider_simple(struct device_node *np,
struct generic_pm_domain *genpd)
{
return __of_genpd_add_provider(np, __of_genpd_xlate_simple, genpd);
}
static inline int of_genpd_add_provider_onecell(struct device_node *np,
struct genpd_onecell_data *data)
{
return __of_genpd_add_provider(np, __of_genpd_xlate_onecell, data);
}
#ifdef CONFIG_PM
extern int dev_pm_domain_attach(struct device *dev, bool power_on);
extern void dev_pm_domain_detach(struct device *dev, bool power_off);
#else
static inline int dev_pm_domain_attach(struct device *dev, bool power_on)
{
return -ENODEV;
}
static inline void dev_pm_domain_detach(struct device *dev, bool power_off) {}
#endif
#endif /* _LINUX_PM_DOMAIN_H */
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