This patch series adds a suspend-block api that provides the same
functionality as the android wakelock api. This version fixes a race
in suspend blocking work, has some documentation changes and
opportunistic suspend now uses the same workqueue as runtime pm.
--
Arve Hjønnevåg <[email protected]>
Adds /sys/power/policy that selects the behaviour of /sys/power/state.
After setting the policy to opportunistic, writes to /sys/power/state
become non-blocking requests that specify which suspend state to enter
when no suspend blockers are active. A special state, "on", stops the
process by activating the "main" suspend blocker.
Signed-off-by: Arve Hjønnevåg <[email protected]>
---
Documentation/power/opportunistic-suspend.txt | 119 +++++++++++
include/linux/suspend_blocker.h | 64 ++++++
kernel/power/Kconfig | 16 ++
kernel/power/Makefile | 1 +
kernel/power/main.c | 92 ++++++++-
kernel/power/power.h | 9 +
kernel/power/suspend.c | 4 +-
kernel/power/suspend_blocker.c | 261 +++++++++++++++++++++++++
8 files changed, 559 insertions(+), 7 deletions(-)
create mode 100644 Documentation/power/opportunistic-suspend.txt
create mode 100755 include/linux/suspend_blocker.h
create mode 100644 kernel/power/suspend_blocker.c
diff --git a/Documentation/power/opportunistic-suspend.txt b/Documentation/power/opportunistic-suspend.txt
new file mode 100644
index 0000000..3d060e8
--- /dev/null
+++ b/Documentation/power/opportunistic-suspend.txt
@@ -0,0 +1,119 @@
+Opportunistic Suspend
+=====================
+
+Opportunistic suspend is a feature allowing the system to be suspended (ie. put
+into one of the available sleep states) automatically whenever it is regarded
+as idle. The suspend blockers framework described below is used to determine
+when that happens.
+
+The /sys/power/policy sysfs attribute is used to switch the system between the
+opportunistic and "forced" suspend behavior, where in the latter case the
+system is only suspended if a specific value, corresponding to one of the
+available system sleep states, is written into /sys/power/state. However, in
+the former, opportunistic, case the system is put into the sleep state
+corresponding to the value written to /sys/power/state whenever there are no
+active suspend blockers. The default policy is "forced". Also, suspend blockers
+do not affect sleep states entered from idle.
+
+When the policy is "opportunisic", there is a special value, "on", that can be
+written to /sys/power/state. This will block the automatic sleep request, as if
+a suspend blocker was used by a device driver. This way the opportunistic
+suspend may be blocked by user space whithout switching back to the "forced"
+mode.
+
+A suspend blocker is an object used to inform the PM subsystem when the system
+can or cannot be suspended in the "opportunistic" mode (the "forced" mode
+ignores suspend blockers). To use it, a device driver creates a struct
+suspend_blocker that must be initialized with suspend_blocker_init(). Before
+freeing the suspend_blocker structure or its name, suspend_blocker_destroy()
+must be called on it.
+
+A suspend blocker is activated using suspend_block(), which prevents the PM
+subsystem from putting the system into the requested sleep state in the
+"opportunistic" mode until the suspend blocker is deactivated with
+suspend_unblock(). Multiple suspend blockers may be active simultaneously, and
+the system will not suspend as long as at least one of them is active.
+
+If opportunistic suspend is already in progress when suspend_block() is called,
+it will abort the suspend, unless suspend_ops->enter has already been
+executed. If suspend is aborted this way, the system is usually not fully
+operational at that point. The suspend callbacks of some drivers may still be
+running and it usually takes time to restore the system to the fully operational
+state.
+
+Here's an example showing how a cell phone or other embedded system can handle
+keystrokes (or other input events) in the presence of suspend blockers. Use
+set_irq_wake or a platform specific api to make sure the keypad interrupt wakes
+up the cpu. Once the keypad driver has resumed, the sequence of events can look
+like this:
+
+- The Keypad driver gets an interrupt. It then calls suspend_block on the
+ keypad-scan suspend_blocker and starts scanning the keypad matrix.
+- The keypad-scan code detects a key change and reports it to the input-event
+ driver.
+- The input-event driver sees the key change, enqueues an event, and calls
+ suspend_block on the input-event-queue suspend_blocker.
+- The keypad-scan code detects that no keys are held and calls suspend_unblock
+ on the keypad-scan suspend_blocker.
+- The user-space input-event thread returns from select/poll, calls
+ suspend_block on the process-input-events suspend_blocker and then calls read
+ on the input-event device.
+- The input-event driver dequeues the key-event and, since the queue is now
+ empty, it calls suspend_unblock on the input-event-queue suspend_blocker.
+- The user-space input-event thread returns from read. If it determines that
+ the key should be ignored, it calls suspend_unblock on the
+ process_input_events suspend_blocker and then calls select or poll. The
+ system will automatically suspend again, since now no suspend blockers are
+ active.
+
+If the key that was pressed instead should preform a simple action (for example,
+adjusting the volume), this action can be performed right before calling
+suspend_unblock on the process_input_events suspend_blocker. However, if the key
+triggers a longer-running action, that action needs its own suspend_blocker and
+suspend_block must be called on that suspend blocker before calling
+suspend_unblock on the process_input_events suspend_blocker.
+
+ Key pressed Key released
+ | |
+keypad-scan ++++++++++++++++++
+input-event-queue +++ +++
+process-input-events +++ +++
+
+
+Driver API
+==========
+
+A driver can use the suspend block api by adding a suspend_blocker variable to
+its state and calling suspend_blocker_init. For instance:
+struct state {
+ struct suspend_blocker suspend_blocker;
+}
+
+init() {
+ suspend_blocker_init(&state->suspend_blocker, "suspend-blocker-name");
+}
+
+Before freeing the memory, suspend_blocker_destroy must be called:
+
+uninit() {
+ suspend_blocker_destroy(&state->suspend_blocker);
+}
+
+When the driver determines that it needs to run (usually in an interrupt
+handler) it calls suspend_block:
+ suspend_block(&state->suspend_blocker);
+
+When it no longer needs to run it calls suspend_unblock:
+ suspend_unblock(&state->suspend_blocker);
+
+Calling suspend_block when the suspend blocker is active or suspend_unblock when
+it is not active has no effect (i.e., these functions don't nest). This allows
+drivers to update their state and call suspend suspend_block or suspend_unblock
+based on the result.
+For instance:
+
+if (list_empty(&state->pending_work))
+ suspend_unblock(&state->suspend_blocker);
+else
+ suspend_block(&state->suspend_blocker);
+
diff --git a/include/linux/suspend_blocker.h b/include/linux/suspend_blocker.h
new file mode 100755
index 0000000..f9928cc
--- /dev/null
+++ b/include/linux/suspend_blocker.h
@@ -0,0 +1,64 @@
+/* include/linux/suspend_blocker.h
+ *
+ * Copyright (C) 2007-2009 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_SUSPEND_BLOCKER_H
+#define _LINUX_SUSPEND_BLOCKER_H
+
+#include <linux/list.h>
+
+/**
+ * struct suspend_blocker - the basic suspend_blocker structure
+ * @link: List entry for active or inactive list.
+ * @flags: Tracks initialized and active state.
+ * @name: Name used for debugging.
+ *
+ * When a suspend_blocker is active it prevents the system from entering
+ * opportunistic suspend.
+ *
+ * The suspend_blocker structure must be initialized by suspend_blocker_init()
+ */
+
+struct suspend_blocker {
+#ifdef CONFIG_OPPORTUNISTIC_SUSPEND
+ struct list_head link;
+ int flags;
+ const char *name;
+#endif
+};
+
+#ifdef CONFIG_OPPORTUNISTIC_SUSPEND
+
+void suspend_blocker_init(struct suspend_blocker *blocker, const char *name);
+void suspend_blocker_destroy(struct suspend_blocker *blocker);
+void suspend_block(struct suspend_blocker *blocker);
+void suspend_unblock(struct suspend_blocker *blocker);
+bool suspend_blocker_is_active(struct suspend_blocker *blocker);
+bool suspend_is_blocked(void);
+
+#else
+
+static inline void suspend_blocker_init(struct suspend_blocker *blocker,
+ const char *name) {}
+static inline void suspend_blocker_destroy(struct suspend_blocker *blocker) {}
+static inline void suspend_block(struct suspend_blocker *blocker) {}
+static inline void suspend_unblock(struct suspend_blocker *blocker) {}
+static inline bool suspend_blocker_is_active(struct suspend_blocker *bl)
+ { return 0; }
+static inline bool suspend_is_blocked(void) { return 0; }
+
+#endif
+
+#endif
+
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 5c36ea9..55a06a1 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -130,6 +130,22 @@ config SUSPEND_FREEZER
Turning OFF this setting is NOT recommended! If in doubt, say Y.
+config OPPORTUNISTIC_SUSPEND
+ bool "Suspend blockers"
+ depends on PM_SLEEP
+ select RTC_LIB
+ default n
+ ---help---
+ Opportunistic sleep support. Allows the system to be put into a sleep
+ state opportunistically, if it doesn't do any useful work at the
+ moment. The PM subsystem is switched into this mode of operation by
+ writing "opportunistic" into /sys/power/policy, while writing
+ "forced" to this file turns the opportunistic suspend feature off.
+ In the "opportunistic" mode suspend blockers are used to determine
+ when to suspend the system and the value written to /sys/power/state
+ determines the sleep state the system will be put into when there are
+ no active suspend blockers.
+
config HIBERNATION_NVS
bool
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index 4319181..ee5276d 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_PM) += main.o
obj-$(CONFIG_PM_SLEEP) += console.o
obj-$(CONFIG_FREEZER) += process.o
obj-$(CONFIG_SUSPEND) += suspend.o
+obj-$(CONFIG_OPPORTUNISTIC_SUSPEND) += suspend_blocker.o
obj-$(CONFIG_PM_TEST_SUSPEND) += suspend_test.o
obj-$(CONFIG_HIBERNATION) += hibernate.o snapshot.o swap.o user.o
obj-$(CONFIG_HIBERNATION_NVS) += hibernate_nvs.o
diff --git a/kernel/power/main.c b/kernel/power/main.c
index b58800b..030ecdc 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -12,6 +12,7 @@
#include <linux/string.h>
#include <linux/resume-trace.h>
#include <linux/workqueue.h>
+#include <linux/suspend_blocker.h>
#include "power.h"
@@ -20,6 +21,27 @@ DEFINE_MUTEX(pm_mutex);
unsigned int pm_flags;
EXPORT_SYMBOL(pm_flags);
+struct policy {
+ const char *name;
+ bool (*valid_state)(suspend_state_t state);
+ int (*set_state)(suspend_state_t state);
+};
+static struct policy policies[] = {
+ {
+ .name = "forced",
+ .valid_state = valid_state,
+ .set_state = enter_state,
+ },
+#ifdef CONFIG_OPPORTUNISTIC_SUSPEND
+ {
+ .name = "opportunistic",
+ .valid_state = request_suspend_valid_state,
+ .set_state = request_suspend_state,
+ },
+#endif
+};
+static int policy;
+
#ifdef CONFIG_PM_SLEEP
/* Routines for PM-transition notifications */
@@ -146,6 +168,12 @@ struct kobject *power_kobj;
*
* store() accepts one of those strings, translates it into the
* proper enumerated value, and initiates a suspend transition.
+ *
+ * If policy is set to opportunistic, store() does not block until the
+ * system resumes, and it will try to re-enter the state until another
+ * state is requested. Suspend blockers are respected and the requested
+ * state will only be entered when no suspend blockers are active.
+ * Write "on" to cancel.
*/
static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
@@ -155,12 +183,13 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
int i;
for (i = 0; i < PM_SUSPEND_MAX; i++) {
- if (pm_states[i] && valid_state(i))
+ if (pm_states[i] && policies[policy].valid_state(i))
s += sprintf(s,"%s ", pm_states[i]);
}
#endif
#ifdef CONFIG_HIBERNATION
- s += sprintf(s, "%s\n", "disk");
+ if (!policy)
+ s += sprintf(s, "%s\n", "disk");
#else
if (s != buf)
/* convert the last space to a newline */
@@ -173,7 +202,7 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
#ifdef CONFIG_SUSPEND
- suspend_state_t state = PM_SUSPEND_STANDBY;
+ suspend_state_t state = PM_SUSPEND_ON;
const char * const *s;
#endif
char *p;
@@ -184,7 +213,7 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
len = p ? p - buf : n;
/* First, check if we are requested to hibernate */
- if (len == 4 && !strncmp(buf, "disk", len)) {
+ if (len == 4 && !strncmp(buf, "disk", len) && !policy) {
error = hibernate();
goto Exit;
}
@@ -195,7 +224,7 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
break;
}
if (state < PM_SUSPEND_MAX && *s)
- error = enter_state(state);
+ error = policies[policy].set_state(state);
#endif
Exit:
@@ -204,6 +233,55 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
power_attr(state);
+/**
+ * policy - set policy for state
+ */
+
+static ssize_t policy_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ char *s = buf;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(policies); i++) {
+ if (i == policy)
+ s += sprintf(s, "[%s] ", policies[i].name);
+ else
+ s += sprintf(s, "%s ", policies[i].name);
+ }
+ if (s != buf)
+ /* convert the last space to a newline */
+ *(s-1) = '\n';
+ return (s - buf);
+}
+
+static ssize_t policy_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t n)
+{
+ const char *s;
+ char *p;
+ int len;
+ int i;
+
+ p = memchr(buf, '\n', n);
+ len = p ? p - buf : n;
+
+ for (i = 0; i < ARRAY_SIZE(policies); i++) {
+ s = policies[i].name;
+ if (s && len == strlen(s) && !strncmp(buf, s, len)) {
+ mutex_lock(&pm_mutex);
+ policies[policy].set_state(PM_SUSPEND_ON);
+ policy = i;
+ mutex_unlock(&pm_mutex);
+ return n;
+ }
+ }
+ return -EINVAL;
+}
+
+power_attr(policy);
+
#ifdef CONFIG_PM_TRACE
int pm_trace_enabled;
@@ -231,6 +309,7 @@ power_attr(pm_trace);
static struct attribute * g[] = {
&state_attr.attr,
+ &policy_attr.attr,
#ifdef CONFIG_PM_TRACE
&pm_trace_attr.attr,
#endif
@@ -247,7 +326,7 @@ static struct attribute_group attr_group = {
.attrs = g,
};
-#ifdef CONFIG_PM_RUNTIME
+#if defined(CONFIG_PM_RUNTIME) || defined(CONFIG_OPPORTUNISTIC_SUSPEND)
struct workqueue_struct *pm_wq;
EXPORT_SYMBOL_GPL(pm_wq);
@@ -266,6 +345,7 @@ static int __init pm_init(void)
int error = pm_start_workqueue();
if (error)
return error;
+ suspend_block_init();
power_kobj = kobject_create_and_add("power", NULL);
if (!power_kobj)
return -ENOMEM;
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 46c5a26..67d10fd 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -236,3 +236,12 @@ static inline void suspend_thaw_processes(void)
{
}
#endif
+
+/* kernel/power/suspend_block.c */
+extern int request_suspend_state(suspend_state_t state);
+extern bool request_suspend_valid_state(suspend_state_t state);
+#ifdef CONFIG_OPPORTUNISTIC_SUSPEND
+extern void __init suspend_block_init(void);
+#else
+static inline void suspend_block_init(void) {}
+#endif
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 56e7dbb..dc42006 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -16,10 +16,12 @@
#include <linux/cpu.h>
#include <linux/syscalls.h>
#include <linux/gfp.h>
+#include <linux/suspend_blocker.h>
#include "power.h"
const char *const pm_states[PM_SUSPEND_MAX] = {
+ [PM_SUSPEND_ON] = "on",
[PM_SUSPEND_STANDBY] = "standby",
[PM_SUSPEND_MEM] = "mem",
};
@@ -157,7 +159,7 @@ static int suspend_enter(suspend_state_t state)
error = sysdev_suspend(PMSG_SUSPEND);
if (!error) {
- if (!suspend_test(TEST_CORE))
+ if (!suspend_is_blocked() && !suspend_test(TEST_CORE))
error = suspend_ops->enter(state);
sysdev_resume();
}
diff --git a/kernel/power/suspend_blocker.c b/kernel/power/suspend_blocker.c
new file mode 100644
index 0000000..2c58b21
--- /dev/null
+++ b/kernel/power/suspend_blocker.c
@@ -0,0 +1,261 @@
+/* kernel/power/suspend_blocker.c
+ *
+ * Copyright (C) 2005-2010 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/suspend.h>
+#include <linux/suspend_blocker.h>
+#include "power.h"
+
+extern struct workqueue_struct *pm_wq;
+
+enum {
+ DEBUG_EXIT_SUSPEND = 1U << 0,
+ DEBUG_WAKEUP = 1U << 1,
+ DEBUG_USER_STATE = 1U << 2,
+ DEBUG_SUSPEND = 1U << 3,
+ DEBUG_SUSPEND_BLOCKER = 1U << 4,
+};
+static int debug_mask = DEBUG_EXIT_SUSPEND | DEBUG_WAKEUP | DEBUG_USER_STATE;
+module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+#define SB_INITIALIZED (1U << 8)
+#define SB_ACTIVE (1U << 9)
+
+static DEFINE_SPINLOCK(list_lock);
+static DEFINE_SPINLOCK(state_lock);
+static LIST_HEAD(inactive_blockers);
+static LIST_HEAD(active_blockers);
+static int current_event_num;
+struct suspend_blocker main_suspend_blocker;
+static suspend_state_t requested_suspend_state = PM_SUSPEND_MEM;
+static bool enable_suspend_blockers;
+
+#define pr_info_time(fmt, args...) \
+ do { \
+ struct timespec ts; \
+ struct rtc_time tm; \
+ getnstimeofday(&ts); \
+ rtc_time_to_tm(ts.tv_sec, &tm); \
+ pr_info(fmt "(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n" , \
+ args, \
+ tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, \
+ tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec); \
+ } while (0);
+
+static void print_active_blockers_locked(void)
+{
+ struct suspend_blocker *blocker;
+
+ list_for_each_entry(blocker, &active_blockers, link)
+ pr_info("active suspend blocker %s\n", blocker->name);
+}
+
+/**
+ * suspend_is_blocked() - Check if suspend should be blocked
+ *
+ * suspend_is_blocked can be used by generic power management code to abort
+ * suspend.
+ *
+ * To preserve backward compatibility suspend_is_blocked returns 0 unless it
+ * is called during suspend initiated from the suspend_block code.
+ */
+bool suspend_is_blocked(void)
+{
+ if (!enable_suspend_blockers)
+ return 0;
+ return !list_empty(&active_blockers);
+}
+
+static void suspend_worker(struct work_struct *work)
+{
+ int ret;
+ int entry_event_num;
+
+ enable_suspend_blockers = true;
+ while (!suspend_is_blocked()) {
+ entry_event_num = current_event_num;
+
+ if (debug_mask & DEBUG_SUSPEND)
+ pr_info("suspend: enter suspend\n");
+
+ ret = pm_suspend(requested_suspend_state);
+
+ if (debug_mask & DEBUG_EXIT_SUSPEND)
+ pr_info_time("suspend: exit suspend, ret = %d ", ret);
+
+ if (current_event_num == entry_event_num)
+ pr_info("suspend: pm_suspend returned with no event\n");
+ }
+ enable_suspend_blockers = false;
+}
+static DECLARE_WORK(suspend_work, suspend_worker);
+
+/**
+ * suspend_blocker_init() - Initialize a suspend blocker
+ * @blocker: The suspend blocker to initialize.
+ * @name: The name of the suspend blocker to show in debug messages.
+ *
+ * The suspend blocker struct and name must not be freed before calling
+ * suspend_blocker_destroy.
+ */
+void suspend_blocker_init(struct suspend_blocker *blocker, const char *name)
+{
+ unsigned long irqflags = 0;
+
+ WARN_ON(!name);
+
+ if (debug_mask & DEBUG_SUSPEND_BLOCKER)
+ pr_info("suspend_blocker_init name=%s\n", name);
+
+ blocker->name = name;
+ blocker->flags = SB_INITIALIZED;
+ INIT_LIST_HEAD(&blocker->link);
+
+ spin_lock_irqsave(&list_lock, irqflags);
+ list_add(&blocker->link, &inactive_blockers);
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(suspend_blocker_init);
+
+/**
+ * suspend_blocker_destroy() - Destroy a suspend blocker
+ * @blocker: The suspend blocker to destroy.
+ */
+void suspend_blocker_destroy(struct suspend_blocker *blocker)
+{
+ unsigned long irqflags;
+ if (WARN_ON(!(blocker->flags & SB_INITIALIZED)))
+ return;
+
+ if (debug_mask & DEBUG_SUSPEND_BLOCKER)
+ pr_info("suspend_blocker_destroy name=%s\n", blocker->name);
+
+ spin_lock_irqsave(&list_lock, irqflags);
+ blocker->flags &= ~SB_INITIALIZED;
+ list_del(&blocker->link);
+ if ((blocker->flags & SB_ACTIVE) && list_empty(&active_blockers))
+ queue_work(pm_wq, &suspend_work);
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(suspend_blocker_destroy);
+
+/**
+ * suspend_block() - Block suspend
+ * @blocker: The suspend blocker to use
+ *
+ * It is safe to call this function from interrupt context.
+ */
+void suspend_block(struct suspend_blocker *blocker)
+{
+ unsigned long irqflags;
+
+ if (WARN_ON(!(blocker->flags & SB_INITIALIZED)))
+ return;
+
+ spin_lock_irqsave(&list_lock, irqflags);
+
+ if (debug_mask & DEBUG_SUSPEND_BLOCKER)
+ pr_info("suspend_block: %s\n", blocker->name);
+
+ blocker->flags |= SB_ACTIVE;
+ list_move(&blocker->link, &active_blockers);
+ current_event_num++;
+
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(suspend_block);
+
+/**
+ * suspend_unblock() - Unblock suspend
+ * @blocker: The suspend blocker to unblock.
+ *
+ * If no other suspend blockers block suspend, the system will suspend.
+ *
+ * It is safe to call this function from interrupt context.
+ */
+void suspend_unblock(struct suspend_blocker *blocker)
+{
+ unsigned long irqflags;
+
+ if (WARN_ON(!(blocker->flags & SB_INITIALIZED)))
+ return;
+
+ spin_lock_irqsave(&list_lock, irqflags);
+
+ if (debug_mask & DEBUG_SUSPEND_BLOCKER)
+ pr_info("suspend_unblock: %s\n", blocker->name);
+
+ list_move(&blocker->link, &inactive_blockers);
+
+ if ((blocker->flags & SB_ACTIVE) && list_empty(&active_blockers))
+ queue_work(pm_wq, &suspend_work);
+ blocker->flags &= ~(SB_ACTIVE);
+ if (blocker == &main_suspend_blocker) {
+ if (debug_mask & DEBUG_SUSPEND)
+ print_active_blockers_locked();
+ }
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(suspend_unblock);
+
+/**
+ * suspend_blocker_is_active() - Test if a suspend blocker is blocking suspend
+ * @blocker: The suspend blocker to check.
+ *
+ * Returns true if the suspend_blocker is currently active.
+ */
+bool suspend_blocker_is_active(struct suspend_blocker *blocker)
+{
+ WARN_ON(!(blocker->flags & SB_INITIALIZED));
+
+ return !!(blocker->flags & SB_ACTIVE);
+}
+EXPORT_SYMBOL(suspend_blocker_is_active);
+
+bool request_suspend_valid_state(suspend_state_t state)
+{
+ return (state == PM_SUSPEND_ON) || valid_state(state);
+}
+
+int request_suspend_state(suspend_state_t state)
+{
+ unsigned long irqflags;
+
+ if (!request_suspend_valid_state(state))
+ return -ENODEV;
+
+ spin_lock_irqsave(&state_lock, irqflags);
+
+ if (debug_mask & DEBUG_USER_STATE)
+ pr_info_time("request_suspend_state: %s (%d->%d) at %lld ",
+ state != PM_SUSPEND_ON ? "sleep" : "wakeup",
+ requested_suspend_state, state,
+ ktime_to_ns(ktime_get()));
+
+ requested_suspend_state = state;
+ if (state == PM_SUSPEND_ON)
+ suspend_block(&main_suspend_blocker);
+ else
+ suspend_unblock(&main_suspend_blocker);
+ spin_unlock_irqrestore(&state_lock, irqflags);
+ return 0;
+}
+
+void __init suspend_block_init(void)
+{
+ suspend_blocker_init(&main_suspend_blocker, "main");
+ suspend_block(&main_suspend_blocker);
+}
--
1.6.5.1
Add a misc device, "suspend_blocker", that allows user-space processes
to block auto suspend. The device has ioctls to create a suspend_blocker,
and to block and unblock suspend. To delete the suspend_blocker, close
the device.
Signed-off-by: Arve Hjønnevåg <[email protected]>
---
Documentation/ioctl/ioctl-number.txt | 3 +-
Documentation/power/opportunistic-suspend.txt | 17 ++++
include/linux/suspend_block_dev.h | 25 +++++
kernel/power/Kconfig | 9 ++
kernel/power/Makefile | 1 +
kernel/power/user_suspend_blocker.c | 128 +++++++++++++++++++++++++
6 files changed, 182 insertions(+), 1 deletions(-)
create mode 100644 include/linux/suspend_block_dev.h
create mode 100644 kernel/power/user_suspend_blocker.c
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index dd5806f..e2458f7 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -254,7 +254,8 @@ Code Seq#(hex) Include File Comments
'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK
linux/ixjuser.h <http://www.quicknet.net>
'r' 00-1F linux/msdos_fs.h and fs/fat/dir.c
-'s' all linux/cdk.h
+'s' all linux/cdk.h conflict!
+'s' all linux/suspend_block_dev.h conflict!
't' 00-7F linux/if_ppp.h
't' 80-8F linux/isdn_ppp.h
't' 90 linux/toshiba.h
diff --git a/Documentation/power/opportunistic-suspend.txt b/Documentation/power/opportunistic-suspend.txt
index 3d060e8..f2b145e 100644
--- a/Documentation/power/opportunistic-suspend.txt
+++ b/Documentation/power/opportunistic-suspend.txt
@@ -117,3 +117,20 @@ if (list_empty(&state->pending_work))
else
suspend_block(&state->suspend_blocker);
+User-space API
+==============
+
+To create a suspend_blocker from user-space, open the suspend_blocker device:
+ fd = open("/dev/suspend_blocker", O_RDWR | O_CLOEXEC);
+then call:
+ ioctl(fd, SUSPEND_BLOCKER_IOCTL_INIT(strlen(name)), name);
+
+To activate a suspend_blocker call:
+ ioctl(fd, SUSPEND_BLOCKER_IOCTL_BLOCK);
+
+To unblock call:
+ ioctl(fd, SUSPEND_BLOCKER_IOCTL_UNBLOCK);
+
+To destroy the suspend_blocker, close the device:
+ close(fd);
+
diff --git a/include/linux/suspend_block_dev.h b/include/linux/suspend_block_dev.h
new file mode 100644
index 0000000..24bc5c7
--- /dev/null
+++ b/include/linux/suspend_block_dev.h
@@ -0,0 +1,25 @@
+/* include/linux/suspend_block_dev.h
+ *
+ * Copyright (C) 2009 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_SUSPEND_BLOCK_DEV_H
+#define _LINUX_SUSPEND_BLOCK_DEV_H
+
+#include <linux/ioctl.h>
+
+#define SUSPEND_BLOCKER_IOCTL_INIT(len) _IOC(_IOC_WRITE, 's', 0, len)
+#define SUSPEND_BLOCKER_IOCTL_BLOCK _IO('s', 1)
+#define SUSPEND_BLOCKER_IOCTL_UNBLOCK _IO('s', 2)
+
+#endif
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 55a06a1..fe5a2f2 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -146,6 +146,15 @@ config OPPORTUNISTIC_SUSPEND
determines the sleep state the system will be put into when there are
no active suspend blockers.
+config USER_SUSPEND_BLOCKERS
+ bool "Userspace suspend blockers"
+ depends on OPPORTUNISTIC_SUSPEND
+ default y
+ ---help---
+ User-space suspend block api. Creates a misc device with ioctls
+ to create, block and unblock a suspend_blocker. The suspend_blocker
+ will be deleted when the device is closed.
+
config HIBERNATION_NVS
bool
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index ee5276d..78f703b 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_PM_SLEEP) += console.o
obj-$(CONFIG_FREEZER) += process.o
obj-$(CONFIG_SUSPEND) += suspend.o
obj-$(CONFIG_OPPORTUNISTIC_SUSPEND) += suspend_blocker.o
+obj-$(CONFIG_USER_SUSPEND_BLOCKERS) += user_suspend_blocker.o
obj-$(CONFIG_PM_TEST_SUSPEND) += suspend_test.o
obj-$(CONFIG_HIBERNATION) += hibernate.o snapshot.o swap.o user.o
obj-$(CONFIG_HIBERNATION_NVS) += hibernate_nvs.o
diff --git a/kernel/power/user_suspend_blocker.c b/kernel/power/user_suspend_blocker.c
new file mode 100644
index 0000000..dc1d06f
--- /dev/null
+++ b/kernel/power/user_suspend_blocker.c
@@ -0,0 +1,128 @@
+/* kernel/power/user_suspend_block.c
+ *
+ * Copyright (C) 2009-2010 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/suspend_blocker.h>
+#include <linux/suspend_block_dev.h>
+
+enum {
+ DEBUG_FAILURE = BIT(0),
+};
+static int debug_mask = DEBUG_FAILURE;
+module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+static DEFINE_MUTEX(ioctl_lock);
+
+struct user_suspend_blocker {
+ struct suspend_blocker blocker;
+ char name[0];
+};
+
+static int create_user_suspend_blocker(struct file *file, void __user *name,
+ size_t name_len)
+{
+ struct user_suspend_blocker *bl;
+ if (file->private_data)
+ return -EBUSY;
+ if (name_len > NAME_MAX)
+ return -ENAMETOOLONG;
+ bl = kzalloc(sizeof(*bl) + name_len + 1, GFP_KERNEL);
+ if (!bl)
+ return -ENOMEM;
+ if (copy_from_user(bl->name, name, name_len))
+ goto err_fault;
+ suspend_blocker_init(&bl->blocker, bl->name);
+ file->private_data = bl;
+ return 0;
+
+err_fault:
+ kfree(bl);
+ return -EFAULT;
+}
+
+static long user_suspend_blocker_ioctl(struct file *file, unsigned int cmd,
+ unsigned long _arg)
+{
+ void __user *arg = (void __user *)_arg;
+ struct user_suspend_blocker *bl;
+ long ret;
+
+ mutex_lock(&ioctl_lock);
+ if ((cmd & ~IOCSIZE_MASK) == SUSPEND_BLOCKER_IOCTL_INIT(0)) {
+ ret = create_user_suspend_blocker(file, arg, _IOC_SIZE(cmd));
+ goto done;
+ }
+ bl = file->private_data;
+ if (!bl) {
+ ret = -ENOENT;
+ goto done;
+ }
+ switch (cmd) {
+ case SUSPEND_BLOCKER_IOCTL_BLOCK:
+ suspend_block(&bl->blocker);
+ ret = 0;
+ break;
+ case SUSPEND_BLOCKER_IOCTL_UNBLOCK:
+ suspend_unblock(&bl->blocker);
+ ret = 0;
+ break;
+ default:
+ ret = -ENOTSUPP;
+ }
+done:
+ if (ret && (debug_mask & DEBUG_FAILURE))
+ pr_err("user_suspend_blocker_ioctl: cmd %x failed, %ld\n",
+ cmd, ret);
+ mutex_unlock(&ioctl_lock);
+ return ret;
+}
+
+static int user_suspend_blocker_release(struct inode *inode, struct file *file)
+{
+ struct user_suspend_blocker *bl = file->private_data;
+ if (!bl)
+ return 0;
+ suspend_blocker_destroy(&bl->blocker);
+ kfree(bl);
+ return 0;
+}
+
+const struct file_operations user_suspend_blocker_fops = {
+ .release = user_suspend_blocker_release,
+ .unlocked_ioctl = user_suspend_blocker_ioctl,
+};
+
+struct miscdevice user_suspend_blocker_device = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "suspend_blocker",
+ .fops = &user_suspend_blocker_fops,
+};
+
+static int __init user_suspend_blocker_init(void)
+{
+ return misc_register(&user_suspend_blocker_device);
+}
+
+static void __exit user_suspend_blocker_exit(void)
+{
+ misc_deregister(&user_suspend_blocker_device);
+}
+
+module_init(user_suspend_blocker_init);
+module_exit(user_suspend_blocker_exit);
--
1.6.5.1
When connecting usb or the charger the device would often go back to sleep
before the charge led and screen turned on.
Signed-off-by: Arve Hjønnevåg <[email protected]>
---
drivers/power/power_supply_core.c | 9 ++++++---
include/linux/power_supply.h | 3 ++-
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index cce75b4..577a131 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -39,7 +39,7 @@ static int __power_supply_changed_work(struct device *dev, void *data)
static void power_supply_changed_work(struct work_struct *work)
{
struct power_supply *psy = container_of(work, struct power_supply,
- changed_work);
+ changed_work.work);
dev_dbg(psy->dev, "%s\n", __func__);
@@ -55,7 +55,7 @@ void power_supply_changed(struct power_supply *psy)
{
dev_dbg(psy->dev, "%s\n", __func__);
- schedule_work(&psy->changed_work);
+ schedule_suspend_blocking_work(&psy->changed_work);
}
EXPORT_SYMBOL_GPL(power_supply_changed);
@@ -155,7 +155,8 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
goto dev_create_failed;
}
- INIT_WORK(&psy->changed_work, power_supply_changed_work);
+ suspend_blocking_work_init(&psy->changed_work,
+ power_supply_changed_work, "power-supply");
rc = power_supply_create_attrs(psy);
if (rc)
@@ -172,6 +173,7 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
create_triggers_failed:
power_supply_remove_attrs(psy);
create_attrs_failed:
+ suspend_blocking_work_destroy(&psy->changed_work);
device_unregister(psy->dev);
dev_create_failed:
success:
@@ -184,6 +186,7 @@ void power_supply_unregister(struct power_supply *psy)
flush_scheduled_work();
power_supply_remove_triggers(psy);
power_supply_remove_attrs(psy);
+ suspend_blocking_work_destroy(&psy->changed_work);
device_unregister(psy->dev);
}
EXPORT_SYMBOL_GPL(power_supply_unregister);
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index ebd2b8f..8a12d50 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -14,6 +14,7 @@
#define __LINUX_POWER_SUPPLY_H__
#include <linux/device.h>
+#include <linux/suspend_blocker.h>
#include <linux/workqueue.h>
#include <linux/leds.h>
@@ -152,7 +153,7 @@ struct power_supply {
/* private */
struct device *dev;
- struct work_struct changed_work;
+ struct suspend_blocking_work changed_work;
#ifdef CONFIG_LEDS_TRIGGERS
struct led_trigger *charging_full_trig;
--
1.6.5.1
Add an ioctl, EVIOCSSUSPENDBLOCK, to enable a suspend_blocker that will block
suspend while the event queue is not empty. This allows userspace code to
process input events while the device appears to be asleep.
Signed-off-by: Arve Hjønnevåg <[email protected]>
---
drivers/input/evdev.c | 22 ++++++++++++++++++++++
include/linux/input.h | 3 +++
2 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 2ee6c7a..66e0d16 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -20,6 +20,7 @@
#include <linux/input.h>
#include <linux/major.h>
#include <linux/device.h>
+#include <linux/suspend_blocker.h>
#include "input-compat.h"
struct evdev {
@@ -43,6 +44,8 @@ struct evdev_client {
struct fasync_struct *fasync;
struct evdev *evdev;
struct list_head node;
+ struct suspend_blocker suspend_blocker;
+ bool use_suspend_blocker;
};
static struct evdev *evdev_table[EVDEV_MINORS];
@@ -55,6 +58,8 @@ static void evdev_pass_event(struct evdev_client *client,
* Interrupts are disabled, just acquire the lock
*/
spin_lock(&client->buffer_lock);
+ if (client->use_suspend_blocker)
+ suspend_block(&client->suspend_blocker);
client->buffer[client->head++] = *event;
client->head &= EVDEV_BUFFER_SIZE - 1;
spin_unlock(&client->buffer_lock);
@@ -234,6 +239,8 @@ static int evdev_release(struct inode *inode, struct file *file)
mutex_unlock(&evdev->mutex);
evdev_detach_client(evdev, client);
+ if (client->use_suspend_blocker)
+ suspend_blocker_destroy(&client->suspend_blocker);
kfree(client);
evdev_close_device(evdev);
@@ -335,6 +342,8 @@ static int evdev_fetch_next_event(struct evdev_client *client,
if (have_event) {
*event = client->buffer[client->tail++];
client->tail &= EVDEV_BUFFER_SIZE - 1;
+ if (client->use_suspend_blocker && client->head == client->tail)
+ suspend_unblock(&client->suspend_blocker);
}
spin_unlock_irq(&client->buffer_lock);
@@ -585,6 +594,19 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
else
return evdev_ungrab(evdev, client);
+ case EVIOCGSUSPENDBLOCK:
+ return put_user(client->use_suspend_blocker, ip);
+
+ case EVIOCSSUSPENDBLOCK:
+ spin_lock_irq(&client->buffer_lock);
+ if (!client->use_suspend_blocker && p)
+ suspend_blocker_init(&client->suspend_blocker, "evdev");
+ else if (client->use_suspend_blocker && !p)
+ suspend_blocker_destroy(&client->suspend_blocker);
+ client->use_suspend_blocker = !!p;
+ spin_unlock_irq(&client->buffer_lock);
+ return 0;
+
default:
if (_IOC_TYPE(cmd) != 'E')
diff --git a/include/linux/input.h b/include/linux/input.h
index 7ed2251..b2d93b4 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -82,6 +82,9 @@ struct input_absinfo {
#define EVIOCGRAB _IOW('E', 0x90, int) /* Grab/Release device */
+#define EVIOCGSUSPENDBLOCK _IOR('E', 0x91, int) /* get suspend block enable */
+#define EVIOCSSUSPENDBLOCK _IOW('E', 0x91, int) /* set suspend block enable */
+
/*
* Event types
*/
--
1.6.5.1
Allow work to be queued that will block suspend while it is pending
or executing. To get the same functionality in the calling code often
requires a separate suspend_blocker for pending and executing work, or
additional state and locking. This implementation does add additional
state and locking, but this can be removed later if we add support for
suspend blocking work to the core workqueue code.
Signed-off-by: Arve Hjønnevåg <[email protected]>
---
include/linux/suspend_blocker.h | 67 ++++++++++++++++++++++++
kernel/power/suspend_blocker.c | 109 +++++++++++++++++++++++++++++++++++++++
2 files changed, 176 insertions(+), 0 deletions(-)
diff --git a/include/linux/suspend_blocker.h b/include/linux/suspend_blocker.h
index c80764c..bf41a57 100755
--- a/include/linux/suspend_blocker.h
+++ b/include/linux/suspend_blocker.h
@@ -18,6 +18,7 @@
#include <linux/list.h>
#include <linux/ktime.h>
+#include <linux/workqueue.h>
/**
* struct suspend_blocker - the basic suspend_blocker structure
@@ -57,6 +58,38 @@ struct suspend_blocker {
#endif
};
+/**
+ * struct suspend_blocking_work - the basic suspend_blocking_work structure
+ * @work: Standard work struct.
+ * @suspend_blocker: Suspend blocker.
+ * @func: Callback.
+ * @lock: Spinlock protecting pending and running state.
+ * @active: Number of cpu workqueues where work is pending or
+ * callback is running.
+ *
+ * When suspend blocking work is pending or its callback is running it prevents
+ * the system from entering opportunistic suspend.
+ *
+ * The suspend_blocking_work structure must be initialized by
+ * suspend_blocking_work_init().
+ */
+
+struct suspend_blocking_work {
+ struct work_struct work;
+#ifdef CONFIG_OPPORTUNISTIC_SUSPEND
+ struct suspend_blocker suspend_blocker;
+ work_func_t func;
+ spinlock_t lock;
+ int active;
+#endif
+};
+
+static inline struct suspend_blocking_work *to_suspend_blocking_work(
+ struct work_struct *work)
+{
+ return container_of(work, struct suspend_blocking_work, work);
+}
+
#ifdef CONFIG_OPPORTUNISTIC_SUSPEND
void suspend_blocker_init(struct suspend_blocker *blocker, const char *name);
@@ -66,6 +99,14 @@ void suspend_unblock(struct suspend_blocker *blocker);
bool suspend_blocker_is_active(struct suspend_blocker *blocker);
bool suspend_is_blocked(void);
+void suspend_blocking_work_init(struct suspend_blocking_work *work,
+ work_func_t func, const char *name);
+void suspend_blocking_work_destroy(struct suspend_blocking_work *work);
+int queue_suspend_blocking_work(struct workqueue_struct *wq,
+ struct suspend_blocking_work *work);
+int schedule_suspend_blocking_work(struct suspend_blocking_work *work);
+int cancel_suspend_blocking_work_sync(struct suspend_blocking_work *work);
+
#else
static inline void suspend_blocker_init(struct suspend_blocker *blocker,
@@ -77,6 +118,32 @@ static inline bool suspend_blocker_is_active(struct suspend_blocker *bl)
{ return 0; }
static inline bool suspend_is_blocked(void) { return 0; }
+static inline void suspend_blocking_work_init(
+ struct suspend_blocking_work *work, work_func_t func, const char *name)
+{
+ INIT_WORK(&work->work, func);
+}
+static inline void suspend_blocking_work_destroy(
+ struct suspend_blocking_work *work)
+{
+ cancel_work_sync(&work->work);
+}
+static inline int queue_suspend_blocking_work(
+ struct workqueue_struct *wq, struct suspend_blocking_work *work)
+{
+ return queue_work(wq, &work->work);
+}
+static inline int schedule_suspend_blocking_work(
+ struct suspend_blocking_work *work)
+{
+ return schedule_work(&work->work);
+}
+static inline int cancel_suspend_blocking_work_sync(
+ struct suspend_blocking_work *work)
+{
+ return cancel_work_sync(&work->work);
+}
+
#endif
#endif
diff --git a/kernel/power/suspend_blocker.c b/kernel/power/suspend_blocker.c
index 77920e6..852d941 100644
--- a/kernel/power/suspend_blocker.c
+++ b/kernel/power/suspend_blocker.c
@@ -474,3 +474,112 @@ static int __init suspend_block_postcore_init(void)
}
postcore_initcall(suspend_block_postcore_init);
+
+static void suspend_blocking_work_complete(struct suspend_blocking_work *work)
+{
+ unsigned long flags;
+
+ WARN_ON(!work->active);
+ spin_lock_irqsave(&work->lock, flags);
+ if (!--work->active)
+ suspend_unblock(&work->suspend_blocker);
+ spin_unlock_irqrestore(&work->lock, flags);
+}
+
+static void suspend_blocking_work_func(struct work_struct *work)
+{
+ struct suspend_blocking_work *sbwork = to_suspend_blocking_work(work);
+
+ sbwork->func(work);
+ suspend_blocking_work_complete(sbwork);
+}
+
+/**
+ * suspend_blocking_work_init - Initialize suspend_blocking_work
+ * @work: The work item in question.
+ * @func: Callback.
+ * @name: Name for suspend blocker.
+ *
+ */
+void suspend_blocking_work_init(struct suspend_blocking_work *work,
+ work_func_t func, const char *name)
+{
+ INIT_WORK(&work->work, suspend_blocking_work_func);
+ suspend_blocker_init(&work->suspend_blocker, name);
+ work->func = func;
+ spin_lock_init(&work->lock);
+ work->active = 0;
+}
+EXPORT_SYMBOL_GPL(suspend_blocking_work_init);
+
+/**
+ * cancel_suspend_blocking_work_sync - Cancel suspend_blocking_work
+ * @work: The work item in question
+ */
+int cancel_suspend_blocking_work_sync(struct suspend_blocking_work *work)
+{
+ int ret;
+
+ ret = cancel_work_sync(&work->work);
+ if (ret)
+ suspend_blocking_work_complete(work);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cancel_suspend_blocking_work_sync);
+
+/**
+ * suspend_blocking_work_destroy - Destroy suspend_blocking_work
+ * @work: The work item in question
+ *
+ * If the work was ever queued on more then one workqueue all but the last
+ * workqueue must be flushed before calling suspend_blocking_work_destroy.
+ */
+void suspend_blocking_work_destroy(struct suspend_blocking_work *work)
+{
+ cancel_suspend_blocking_work_sync(work);
+ WARN_ON(work->active);
+ suspend_blocker_destroy(&work->suspend_blocker);
+}
+EXPORT_SYMBOL_GPL(suspend_blocking_work_destroy);
+
+/**
+ * queue_suspend_blocking_work - Queue suspend blocking work
+ * @wq: Workqueue to queue work on.
+ * @work: The work item in question.
+ */
+int queue_suspend_blocking_work(struct workqueue_struct *wq,
+ struct suspend_blocking_work *work)
+{
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&work->lock, flags);
+ ret = queue_work(wq, &work->work);
+ if (ret) {
+ suspend_block(&work->suspend_blocker);
+ work->active++;
+ }
+ spin_unlock_irqrestore(&work->lock, flags);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(queue_suspend_blocking_work);
+
+/**
+ * schedule_suspend_blocking_work - Queue suspend blocking work
+ * @work: The work item in question.
+ */
+int schedule_suspend_blocking_work(struct suspend_blocking_work *work)
+{
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&work->lock, flags);
+ ret = schedule_work(&work->work);
+ if (ret) {
+ suspend_block(&work->suspend_blocker);
+ work->active++;
+ }
+ spin_unlock_irqrestore(&work->lock, flags);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(schedule_suspend_blocking_work);
--
1.6.5.1
Report suspend block stats in /sys/kernel/debug/suspend_blockers.
Signed-off-by: Arve Hjønnevåg <[email protected]>
---
include/linux/suspend_blocker.h | 21 ++++-
kernel/power/Kconfig | 7 ++
kernel/power/power.h | 5 +
kernel/power/suspend.c | 4 +-
kernel/power/suspend_blocker.c | 190 +++++++++++++++++++++++++++++++++++++--
5 files changed, 218 insertions(+), 9 deletions(-)
diff --git a/include/linux/suspend_blocker.h b/include/linux/suspend_blocker.h
index f9928cc..c80764c 100755
--- a/include/linux/suspend_blocker.h
+++ b/include/linux/suspend_blocker.h
@@ -17,12 +17,21 @@
#define _LINUX_SUSPEND_BLOCKER_H
#include <linux/list.h>
+#include <linux/ktime.h>
/**
* struct suspend_blocker - the basic suspend_blocker structure
* @link: List entry for active or inactive list.
- * @flags: Tracks initialized and active state.
+ * @flags: Tracks initialized, active and stats state.
* @name: Name used for debugging.
+ * @count: Number of times this blocker has been deacivated
+ * @wakeup_count: Number of times this blocker was the first to block suspend
+ * after resume.
+ * @total_time: Total time this suspend blocker has prevented suspend.
+ * @prevent_suspend_time: Time this suspend blocker has prevented suspend while
+ * user-space requested suspend.
+ * @max_time: Max time this suspend blocker has been continuously active
+ * @last_time: Monotonic clock when the active state last changed.
*
* When a suspend_blocker is active it prevents the system from entering
* opportunistic suspend.
@@ -35,6 +44,16 @@ struct suspend_blocker {
struct list_head link;
int flags;
const char *name;
+#ifdef CONFIG_SUSPEND_BLOCKER_STATS
+ struct {
+ int count;
+ int wakeup_count;
+ ktime_t total_time;
+ ktime_t prevent_suspend_time;
+ ktime_t max_time;
+ ktime_t last_time;
+ } stat;
+#endif
#endif
};
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index fe5a2f2..4bcba07 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -146,6 +146,13 @@ config OPPORTUNISTIC_SUSPEND
determines the sleep state the system will be put into when there are
no active suspend blockers.
+config SUSPEND_BLOCKER_STATS
+ bool "Suspend block stats"
+ depends on OPPORTUNISTIC_SUSPEND
+ default y
+ ---help---
+ Report suspend block stats in /sys/kernel/debug/suspend_blockers
+
config USER_SUSPEND_BLOCKERS
bool "Userspace suspend blockers"
depends on OPPORTUNISTIC_SUSPEND
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 67d10fd..897c116 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -245,3 +245,8 @@ extern void __init suspend_block_init(void);
#else
static inline void suspend_block_init(void) {}
#endif
+#ifdef CONFIG_SUSPEND_BLOCKER_STATS
+void about_to_enter_suspend(void);
+#else
+static inline void about_to_enter_suspend(void) {}
+#endif
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index dc42006..6d327ea 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -159,8 +159,10 @@ static int suspend_enter(suspend_state_t state)
error = sysdev_suspend(PMSG_SUSPEND);
if (!error) {
- if (!suspend_is_blocked() && !suspend_test(TEST_CORE))
+ if (!suspend_is_blocked() && !suspend_test(TEST_CORE)) {
+ about_to_enter_suspend();
error = suspend_ops->enter(state);
+ }
sysdev_resume();
}
diff --git a/kernel/power/suspend_blocker.c b/kernel/power/suspend_blocker.c
index ced4993..77920e6 100644
--- a/kernel/power/suspend_blocker.c
+++ b/kernel/power/suspend_blocker.c
@@ -34,6 +34,7 @@ module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
#define SB_INITIALIZED (1U << 8)
#define SB_ACTIVE (1U << 9)
+#define SB_PREVENTING_SUSPEND (1U << 10)
static DEFINE_SPINLOCK(list_lock);
static DEFINE_SPINLOCK(state_lock);
@@ -43,6 +44,7 @@ static int current_event_num;
struct suspend_blocker main_suspend_blocker;
static suspend_state_t requested_suspend_state = PM_SUSPEND_MEM;
static bool enable_suspend_blockers;
+static struct suspend_blocker unknown_wakeup;
static struct dentry *suspend_blocker_stats_dentry;
#define pr_info_time(fmt, args...) \
@@ -57,6 +59,153 @@ static struct dentry *suspend_blocker_stats_dentry;
tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec); \
} while (0);
+#ifdef CONFIG_SUSPEND_BLOCKER_STATS
+static struct suspend_blocker deleted_suspend_blockers;
+static ktime_t last_sleep_time_update;
+static bool wait_for_wakeup;
+
+static int print_blocker_stat(struct seq_file *m,
+ struct suspend_blocker *blocker)
+{
+ int lock_count = blocker->stat.count;
+ ktime_t active_time = ktime_set(0, 0);
+ ktime_t total_time = blocker->stat.total_time;
+ ktime_t max_time = blocker->stat.max_time;
+ ktime_t prevent_suspend_time = blocker->stat.prevent_suspend_time;
+ if (blocker->flags & SB_ACTIVE) {
+ ktime_t now, add_time;
+ now = ktime_get();
+ add_time = ktime_sub(now, blocker->stat.last_time);
+ lock_count++;
+ active_time = add_time;
+ total_time = ktime_add(total_time, add_time);
+ if (blocker->flags & SB_PREVENTING_SUSPEND)
+ prevent_suspend_time = ktime_add(prevent_suspend_time,
+ ktime_sub(now, last_sleep_time_update));
+ if (add_time.tv64 > max_time.tv64)
+ max_time = add_time;
+ }
+
+ return seq_printf(m, "\"%s\"\t%d\t%d\t%lld\t%lld\t%lld\t%lld\t%lld\n",
+ blocker->name, lock_count, blocker->stat.wakeup_count,
+ ktime_to_ns(active_time), ktime_to_ns(total_time),
+ ktime_to_ns(prevent_suspend_time), ktime_to_ns(max_time),
+ ktime_to_ns(blocker->stat.last_time));
+}
+
+
+static int suspend_blocker_stats_show(struct seq_file *m, void *unused)
+{
+ unsigned long irqflags;
+ struct suspend_blocker *blocker;
+
+ seq_puts(m, "name\tcount\twake_count\tactive_since"
+ "\ttotal_time\tsleep_time\tmax_time\tlast_change\n");
+ spin_lock_irqsave(&list_lock, irqflags);
+ list_for_each_entry(blocker, &inactive_blockers, link)
+ print_blocker_stat(m, blocker);
+ list_for_each_entry(blocker, &active_blockers, link)
+ print_blocker_stat(m, blocker);
+ spin_unlock_irqrestore(&list_lock, irqflags);
+ return 0;
+}
+
+static void suspend_blocker_stat_init_locked(struct suspend_blocker *blocker)
+{
+ blocker->stat.count = 0;
+ blocker->stat.wakeup_count = 0;
+ blocker->stat.total_time = ktime_set(0, 0);
+ blocker->stat.prevent_suspend_time = ktime_set(0, 0);
+ blocker->stat.max_time = ktime_set(0, 0);
+ blocker->stat.last_time = ktime_set(0, 0);
+}
+
+static void suspend_blocker_stat_destroy_locked(struct suspend_blocker *bl)
+{
+ if (!bl->stat.count)
+ return;
+ deleted_suspend_blockers.stat.count += bl->stat.count;
+ deleted_suspend_blockers.stat.total_time = ktime_add(
+ deleted_suspend_blockers.stat.total_time, bl->stat.total_time);
+ deleted_suspend_blockers.stat.prevent_suspend_time = ktime_add(
+ deleted_suspend_blockers.stat.prevent_suspend_time,
+ bl->stat.prevent_suspend_time);
+ deleted_suspend_blockers.stat.max_time = ktime_add(
+ deleted_suspend_blockers.stat.max_time, bl->stat.max_time);
+}
+
+static void suspend_unblock_stat_locked(struct suspend_blocker *blocker)
+{
+ ktime_t duration;
+ ktime_t now;
+ if (!(blocker->flags & SB_ACTIVE))
+ return;
+ now = ktime_get();
+ blocker->stat.count++;
+ duration = ktime_sub(now, blocker->stat.last_time);
+ blocker->stat.total_time =
+ ktime_add(blocker->stat.total_time, duration);
+ if (ktime_to_ns(duration) > ktime_to_ns(blocker->stat.max_time))
+ blocker->stat.max_time = duration;
+ blocker->stat.last_time = ktime_get();
+ if (blocker->flags & SB_PREVENTING_SUSPEND) {
+ duration = ktime_sub(now, last_sleep_time_update);
+ blocker->stat.prevent_suspend_time = ktime_add(
+ blocker->stat.prevent_suspend_time, duration);
+ blocker->flags &= ~SB_PREVENTING_SUSPEND;
+ }
+}
+
+static void suspend_block_stat_locked(struct suspend_blocker *blocker)
+{
+ if (wait_for_wakeup) {
+ if (debug_mask & DEBUG_WAKEUP)
+ pr_info("wakeup suspend blocker: %s\n", blocker->name);
+ wait_for_wakeup = false;
+ blocker->stat.wakeup_count++;
+ }
+ if (!(blocker->flags & SB_ACTIVE))
+ blocker->stat.last_time = ktime_get();
+}
+
+static void update_sleep_wait_stats_locked(bool done)
+{
+ struct suspend_blocker *blocker;
+ ktime_t now, elapsed, add;
+
+ now = ktime_get();
+ elapsed = ktime_sub(now, last_sleep_time_update);
+ list_for_each_entry(blocker, &active_blockers, link) {
+ if (blocker->flags & SB_PREVENTING_SUSPEND) {
+ add = elapsed;
+ blocker->stat.prevent_suspend_time = ktime_add(
+ blocker->stat.prevent_suspend_time, add);
+ }
+ if (done)
+ blocker->flags &= ~SB_PREVENTING_SUSPEND;
+ else
+ blocker->flags |= SB_PREVENTING_SUSPEND;
+ }
+ last_sleep_time_update = now;
+}
+
+void about_to_enter_suspend(void)
+{
+ wait_for_wakeup = true;
+}
+
+#else
+
+static inline void suspend_blocker_stat_init_locked(
+ struct suspend_blocker *blocker) {}
+static inline void suspend_blocker_stat_destroy_locked(
+ struct suspend_blocker *blocker) {}
+static inline void suspend_block_stat_locked(
+ struct suspend_blocker *blocker) {}
+static inline void suspend_unblock_stat_locked(
+ struct suspend_blocker *blocker) {}
+static inline void update_sleep_wait_stats_locked(bool done) {}
+
static int suspend_blocker_stats_show(struct seq_file *m, void *unused)
{
unsigned long irqflags;
@@ -72,6 +221,8 @@ static int suspend_blocker_stats_show(struct seq_file *m, void *unused)
return 0;
}
+#endif
+
static void print_active_blockers_locked(void)
{
struct suspend_blocker *blocker;
@@ -102,20 +253,31 @@ static void suspend_worker(struct work_struct *work)
int entry_event_num;
enable_suspend_blockers = true;
- while (!suspend_is_blocked()) {
- entry_event_num = current_event_num;
+ if (suspend_is_blocked()) {
if (debug_mask & DEBUG_SUSPEND)
- pr_info("suspend: enter suspend\n");
+ pr_info("suspend: abort suspend\n");
+ goto abort;
+ }
+
+ entry_event_num = current_event_num;
- ret = pm_suspend(requested_suspend_state);
+ if (debug_mask & DEBUG_SUSPEND)
+ pr_info("suspend: enter suspend\n");
- if (debug_mask & DEBUG_EXIT_SUSPEND)
- pr_info_time("suspend: exit suspend, ret = %d ", ret);
+ ret = pm_suspend(requested_suspend_state);
- if (current_event_num == entry_event_num)
+ if (debug_mask & DEBUG_EXIT_SUSPEND)
+ pr_info_time("suspend: exit suspend, ret = %d ", ret);
+
+ if (current_event_num == entry_event_num) {
+ if (debug_mask & DEBUG_SUSPEND)
pr_info("suspend: pm_suspend returned with no event\n");
+
+ suspend_block(&unknown_wakeup);
+ suspend_unblock(&unknown_wakeup);
}
+abort:
enable_suspend_blockers = false;
}
static DECLARE_WORK(suspend_work, suspend_worker);
@@ -142,6 +304,7 @@ void suspend_blocker_init(struct suspend_blocker *blocker, const char *name)
INIT_LIST_HEAD(&blocker->link);
spin_lock_irqsave(&list_lock, irqflags);
+ suspend_blocker_stat_init_locked(blocker);
list_add(&blocker->link, &inactive_blockers);
spin_unlock_irqrestore(&list_lock, irqflags);
}
@@ -161,6 +324,7 @@ void suspend_blocker_destroy(struct suspend_blocker *blocker)
pr_info("suspend_blocker_destroy name=%s\n", blocker->name);
spin_lock_irqsave(&list_lock, irqflags);
+ suspend_blocker_stat_destroy_locked(blocker);
blocker->flags &= ~SB_INITIALIZED;
list_del(&blocker->link);
if ((blocker->flags & SB_ACTIVE) && list_empty(&active_blockers))
@@ -187,9 +351,14 @@ void suspend_block(struct suspend_blocker *blocker)
if (debug_mask & DEBUG_SUSPEND_BLOCKER)
pr_info("suspend_block: %s\n", blocker->name);
+ suspend_block_stat_locked(blocker);
blocker->flags |= SB_ACTIVE;
list_move(&blocker->link, &active_blockers);
current_event_num++;
+ if (blocker == &main_suspend_blocker)
+ update_sleep_wait_stats_locked(true);
+ else if (!suspend_blocker_is_active(&main_suspend_blocker))
+ update_sleep_wait_stats_locked(false);
spin_unlock_irqrestore(&list_lock, irqflags);
}
@@ -215,6 +384,7 @@ void suspend_unblock(struct suspend_blocker *blocker)
if (debug_mask & DEBUG_SUSPEND_BLOCKER)
pr_info("suspend_unblock: %s\n", blocker->name);
+ suspend_unblock_stat_locked(blocker);
list_move(&blocker->link, &inactive_blockers);
if ((blocker->flags & SB_ACTIVE) && list_empty(&active_blockers))
@@ -223,6 +393,7 @@ void suspend_unblock(struct suspend_blocker *blocker)
if (blocker == &main_suspend_blocker) {
if (debug_mask & DEBUG_SUSPEND)
print_active_blockers_locked();
+ update_sleep_wait_stats_locked(false);
}
spin_unlock_irqrestore(&list_lock, irqflags);
}
@@ -288,6 +459,11 @@ void __init suspend_block_init(void)
{
suspend_blocker_init(&main_suspend_blocker, "main");
suspend_block(&main_suspend_blocker);
+ suspend_blocker_init(&unknown_wakeup, "unknown_wakeups");
+#ifdef CONFIG_SUSPEND_BLOCKER_STATS
+ suspend_blocker_init(&deleted_suspend_blockers,
+ "deleted_suspend_blockers");
+#endif
}
static int __init suspend_block_postcore_init(void)
--
1.6.5.1
Report active and inactive suspend blockers in
/sys/kernel/debug/suspend_blockers.
Signed-off-by: Arve Hjønnevåg <[email protected]>
---
kernel/power/suspend_blocker.c | 43 ++++++++++++++++++++++++++++++++++++++-
1 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/kernel/power/suspend_blocker.c b/kernel/power/suspend_blocker.c
index 2c58b21..ced4993 100644
--- a/kernel/power/suspend_blocker.c
+++ b/kernel/power/suspend_blocker.c
@@ -17,6 +17,7 @@
#include <linux/rtc.h>
#include <linux/suspend.h>
#include <linux/suspend_blocker.h>
+#include <linux/debugfs.h>
#include "power.h"
extern struct workqueue_struct *pm_wq;
@@ -42,6 +43,7 @@ static int current_event_num;
struct suspend_blocker main_suspend_blocker;
static suspend_state_t requested_suspend_state = PM_SUSPEND_MEM;
static bool enable_suspend_blockers;
+static struct dentry *suspend_blocker_stats_dentry;
#define pr_info_time(fmt, args...) \
do { \
@@ -55,6 +57,21 @@ static bool enable_suspend_blockers;
tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec); \
} while (0);
+static int suspend_blocker_stats_show(struct seq_file *m, void *unused)
+{
+ unsigned long irqflags;
+ struct suspend_blocker *blocker;
+
+ seq_puts(m, "name\tactive\n");
+ spin_lock_irqsave(&list_lock, irqflags);
+ list_for_each_entry(blocker, &inactive_blockers, link)
+ seq_printf(m, "\"%s\"\t0\n", blocker->name);
+ list_for_each_entry(blocker, &active_blockers, link)
+ seq_printf(m, "\"%s\"\t1\n", blocker->name);
+ spin_unlock_irqrestore(&list_lock, irqflags);
+ return 0;
+}
+
static void print_active_blockers_locked(void)
{
struct suspend_blocker *blocker;
@@ -106,8 +123,8 @@ static DECLARE_WORK(suspend_work, suspend_worker);
/**
* suspend_blocker_init() - Initialize a suspend blocker
* @blocker: The suspend blocker to initialize.
- * @name: The name of the suspend blocker to show in debug messages.
- *
+ * @name: The name of the suspend blocker to show in debug messages and
+ * /sys/kernel/debug/suspend_blockers.
* The suspend blocker struct and name must not be freed before calling
* suspend_blocker_destroy.
*/
@@ -254,8 +271,30 @@ int request_suspend_state(suspend_state_t state)
return 0;
}
+static int suspend_blocker_stats_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, suspend_blocker_stats_show, NULL);
+}
+
+static const struct file_operations suspend_blocker_stats_fops = {
+ .owner = THIS_MODULE,
+ .open = suspend_blocker_stats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
void __init suspend_block_init(void)
{
suspend_blocker_init(&main_suspend_blocker, "main");
suspend_block(&main_suspend_blocker);
}
+
+static int __init suspend_block_postcore_init(void)
+{
+ suspend_blocker_stats_dentry = debugfs_create_file("suspend_blockers",
+ S_IRUGO, NULL, NULL, &suspend_blocker_stats_fops);
+ return 0;
+}
+
+postcore_initcall(suspend_block_postcore_init);
--
1.6.5.1
If a suspend_blocker is active, suspend will fail anyway. Since
try_to_freeze_tasks can take up to 20 seconds to complete or fail, aborting
as soon as someone blocks suspend (e.g. from an interrupt handler) improves
the worst case wakeup latency.
On an older kernel where task freezing could fail for processes attached
to a debugger, this fixed a problem where the device sometimes hung for
20 seconds before the screen turned on.
Signed-off-by: Arve Hjønnevåg <[email protected]>
---
kernel/power/process.c | 12 ++++++++++--
1 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 71ae290..d8ebd50 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -15,6 +15,7 @@
#include <linux/syscalls.h>
#include <linux/freezer.h>
#include <linux/delay.h>
+#include <linux/suspend_blocker.h>
/*
* Timeout for stopping processes
@@ -38,6 +39,7 @@ static int try_to_freeze_tasks(bool sig_only)
struct timeval start, end;
u64 elapsed_csecs64;
unsigned int elapsed_csecs;
+ bool wakeup = false;
do_gettimeofday(&start);
@@ -63,6 +65,10 @@ static int try_to_freeze_tasks(bool sig_only)
todo++;
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
+ if (todo && suspend_is_blocked()) {
+ wakeup = true;
+ break;
+ }
if (!todo || time_after(jiffies, end_time))
break;
@@ -85,13 +91,15 @@ static int try_to_freeze_tasks(bool sig_only)
* but it cleans up leftover PF_FREEZE requests.
*/
printk("\n");
- printk(KERN_ERR "Freezing of tasks failed after %d.%02d seconds "
+ printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds "
"(%d tasks refusing to freeze):\n",
+ wakeup ? "aborted" : "failed",
elapsed_csecs / 100, elapsed_csecs % 100, todo);
read_lock(&tasklist_lock);
do_each_thread(g, p) {
task_lock(p);
- if (freezing(p) && !freezer_should_skip(p))
+ if (freezing(p) && !freezer_should_skip(p)
+ && elapsed_csecs > 100)
sched_show_task(p);
cancel_freezing(p);
task_unlock(p);
--
1.6.5.1