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-rw-r--r--drivers/base/power/main.c73
-rw-r--r--kernel/power/Kconfig16
-rw-r--r--kernel/power/user.c20
3 files changed, 99 insertions, 10 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 9f098a8..ee039af 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -30,6 +30,8 @@
#include <linux/suspend.h>
#include <trace/events/power.h>
#include <linux/cpuidle.h>
+#include <linux/timer.h>
+
#include "../base.h"
#include "power.h"
@@ -390,6 +392,71 @@ static int dpm_run_callback(pm_callback_t cb, struct device *dev,
return error;
}
+#ifdef CONFIG_DPM_WATCHDOG
+struct dpm_watchdog {
+ struct device *dev;
+ struct task_struct *tsk;
+ struct timer_list timer;
+};
+
+#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
+ struct dpm_watchdog wd
+
+/**
+ * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
+ * @data: Watchdog object address.
+ *
+ * Called when a driver has timed out suspending or resuming.
+ * There's not much we can do here to recover so panic() to
+ * capture a crash-dump in pstore.
+ */
+static void dpm_watchdog_handler(unsigned long data)
+{
+ struct dpm_watchdog *wd = (void *)data;
+
+ dev_emerg(wd->dev, "**** DPM device timeout ****\n");
+ show_stack(wd->tsk, NULL);
+ panic("%s %s: unrecoverable failure\n",
+ dev_driver_string(wd->dev), dev_name(wd->dev));
+}
+
+/**
+ * dpm_watchdog_set - Enable pm watchdog for given device.
+ * @wd: Watchdog. Must be allocated on the stack.
+ * @dev: Device to handle.
+ */
+static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
+{
+ struct timer_list *timer = &wd->timer;
+
+ wd->dev = dev;
+ wd->tsk = current;
+
+ init_timer_on_stack(timer);
+ /* use same timeout value for both suspend and resume */
+ timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
+ timer->function = dpm_watchdog_handler;
+ timer->data = (unsigned long)wd;
+ add_timer(timer);
+}
+
+/**
+ * dpm_watchdog_clear - Disable suspend/resume watchdog.
+ * @wd: Watchdog to disable.
+ */
+static void dpm_watchdog_clear(struct dpm_watchdog *wd)
+{
+ struct timer_list *timer = &wd->timer;
+
+ del_timer_sync(timer);
+ destroy_timer_on_stack(timer);
+}
+#else
+#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
+#define dpm_watchdog_set(x, y)
+#define dpm_watchdog_clear(x)
+#endif
+
/*------------------------- Resume routines -------------------------*/
/**
@@ -576,6 +643,7 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
pm_callback_t callback = NULL;
char *info = NULL;
int error = 0;
+ DECLARE_DPM_WATCHDOG_ON_STACK(wd);
TRACE_DEVICE(dev);
TRACE_RESUME(0);
@@ -584,6 +652,7 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
goto Complete;
dpm_wait(dev->parent, async);
+ dpm_watchdog_set(&wd, dev);
device_lock(dev);
/*
@@ -642,6 +711,7 @@ static int device_resume(struct device *dev, pm_message_t state, bool async)
Unlock:
device_unlock(dev);
+ dpm_watchdog_clear(&wd);
Complete:
complete_all(&dev->power.completion);
@@ -1060,6 +1130,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
pm_callback_t callback = NULL;
char *info = NULL;
int error = 0;
+ DECLARE_DPM_WATCHDOG_ON_STACK(wd);
dpm_wait_for_children(dev, async);
@@ -1083,6 +1154,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
if (dev->power.syscore)
goto Complete;
+ dpm_watchdog_set(&wd, dev);
device_lock(dev);
if (dev->pm_domain) {
@@ -1139,6 +1211,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
}
device_unlock(dev);
+ dpm_watchdog_clear(&wd);
Complete:
complete_all(&dev->power.completion);
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index d444c4e..2fac9cc 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -178,6 +178,22 @@ config PM_SLEEP_DEBUG
def_bool y
depends on PM_DEBUG && PM_SLEEP
+config DPM_WATCHDOG
+ bool "Device suspend/resume watchdog"
+ depends on PM_DEBUG && PSTORE
+ ---help---
+ Sets up a watchdog timer to capture drivers that are
+ locked up attempting to suspend/resume a device.
+ A detected lockup causes system panic with message
+ captured in pstore device for inspection in subsequent
+ boot session.
+
+config DPM_WATCHDOG_TIMEOUT
+ int "Watchdog timeout in seconds"
+ range 1 120
+ default 12
+ depends on DPM_WATCHDOG
+
config PM_TRACE
bool
help
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 957f061..2485027 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -36,9 +36,9 @@ static struct snapshot_data {
struct snapshot_handle handle;
int swap;
int mode;
- char frozen;
- char ready;
- char platform_support;
+ bool frozen;
+ bool ready;
+ bool platform_support;
bool free_bitmaps;
} snapshot_state;
@@ -93,9 +93,9 @@ static int snapshot_open(struct inode *inode, struct file *filp)
if (error)
atomic_inc(&snapshot_device_available);
- data->frozen = 0;
- data->ready = 0;
- data->platform_support = 0;
+ data->frozen = false;
+ data->ready = false;
+ data->platform_support = false;
Unlock:
unlock_system_sleep();
@@ -229,7 +229,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
if (error)
thaw_processes();
else
- data->frozen = 1;
+ data->frozen = true;
break;
@@ -240,7 +240,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
free_basic_memory_bitmaps();
data->free_bitmaps = false;
thaw_processes();
- data->frozen = 0;
+ data->frozen = false;
break;
case SNAPSHOT_CREATE_IMAGE:
@@ -270,7 +270,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
case SNAPSHOT_FREE:
swsusp_free();
memset(&data->handle, 0, sizeof(struct snapshot_handle));
- data->ready = 0;
+ data->ready = false;
/*
* It is necessary to thaw kernel threads here, because
* SNAPSHOT_CREATE_IMAGE may be invoked directly after
@@ -334,7 +334,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
* PM_HIBERNATION_PREPARE
*/
error = suspend_devices_and_enter(PM_SUSPEND_MEM);
- data->ready = 0;
+ data->ready = false;
break;
case SNAPSHOT_PLATFORM_SUPPORT:
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