[PATCH v2] PM / sleep: Mechanism to find source aborting kernel suspend transition
From: Vimal Kumar
Date: Sun Dec 10 2023 - 05:04:22 EST
Sometimes kernel suspend transitions can be aborted unconditionally by
manipulating pm_abort_suspend value using "hard" wakeup triggers or
through "pm_system_wakeup()".
There is no way to trace the source path of module or subsystem which
aborted the suspend transitions. This change will create a list of
wakeup sources aborting suspend in progress through "hard" events as
well as subsytems aborting suspend using "pm_system_wakeup()".
Example: Existing suspend failure logs:
[ 349.708359] PM: Some devices failed to suspend, or early wake event detected
[ 350.327842] PM: suspend exit
Suspend failure logs with this change:
[ 518.761835] PM: Some devices failed to suspend, or early wake event detected
[ 519.486939] PM: wakeup source or subsystem uart_suspend_port aborted suspend
[ 519.500594] PM: suspend exit
Here we can clearly identify the module triggerring abort suspend.
Co-developed-by: Chinmoy Ghosh <chinmoyghosh2001@xxxxxxxxx>
Signed-off-by: Chinmoy Ghosh <chinmoyghosh2001@xxxxxxxxx>
Co-developed-by: Mintu Patel <mintupatel89@xxxxxxxxx>
Signed-off-by: Mintu Patel <mintupatel89@xxxxxxxxx>
Co-developed-by: Vishal Badole <badolevishal1116@xxxxxxxxx>
Signed-off-by: Vishal Badole <badolevishal1116@xxxxxxxxx>
Signed-off-by: Vimal Kumar <vimal.kumar32@xxxxxxxxx>
---
Changes in v2:
- Make pm_abort_suspend_list static.
- Added locks.
- Removed list_empty check as not needed.
- Fix Doc format.
- Fix function name as per global functions.
- Removed use of unlikely/likely.
- Removed extra logging for kmalloc failure.
- Use *info instead of struct name.
---
drivers/base/power/wakeup.c | 82 ++++++++++++++++++++++++++++++++++++-
include/linux/suspend.h | 2 +
kernel/power/suspend.c | 1 +
3 files changed, 84 insertions(+), 1 deletion(-)
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index a917219feea6..fa1e3369b0f6 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -73,6 +73,15 @@ static struct wakeup_source deleted_ws = {
static DEFINE_IDA(wakeup_ida);
+#define MAX_SUSPEND_ABORT_LEN 256
+static DEFINE_RAW_SPINLOCK(abort_suspend_lock);
+
+struct pm_abort_suspend_source {
+ struct list_head list;
+ char *source_triggering_abort_suspend;
+};
+static LIST_HEAD(pm_abort_suspend_list);
+
/**
* wakeup_source_create - Create a struct wakeup_source object.
* @name: Name of the new wakeup source.
@@ -575,6 +584,56 @@ static void wakeup_source_activate(struct wakeup_source *ws)
trace_wakeup_source_activate(ws->name, cec);
}
+/**
+ * abort_suspend_list_clear - Clear pm_abort_suspend_list.
+ *
+ * The pm_abort_suspend_list will be cleared when system PM exits.
+ */
+void abort_suspend_list_clear(void)
+{
+ struct pm_abort_suspend_source *info, *tmp;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&abort_suspend_lock, flags);
+ list_for_each_entry_safe(info, tmp, &pm_abort_suspend_list, list) {
+ list_del(&info->list);
+ kfree(info);
+ }
+ raw_spin_unlock_irqrestore(&abort_suspend_lock, flags);
+}
+EXPORT_SYMBOL_GPL(abort_suspend_list_clear);
+
+/**
+ * pm_abort_suspend_source_add - Update pm_abort_suspend_list
+ * @source_name: Wakeup_source or function aborting suspend transitions.
+ *
+ * Add the source name responsible for updating the abort_suspend flag in the
+ * pm_abort_suspend_list.
+ */
+static void pm_abort_suspend_source_add(const char *source_name)
+{
+ struct pm_abort_suspend_source *info;
+ unsigned long flags;
+
+ info = kmalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return;
+
+ /* Initialize the list within the struct if it's not already initialized */
+ if (list_empty(&info->list))
+ INIT_LIST_HEAD(&info->list);
+
+ info->source_triggering_abort_suspend = kstrdup(source_name, GFP_KERNEL);
+ if (!info->source_triggering_abort_suspend) {
+ kfree(info);
+ return;
+ }
+
+ raw_spin_lock_irqsave(&abort_suspend_lock, flags);
+ list_add_tail(&info->list, &pm_abort_suspend_list);
+ raw_spin_unlock_irqrestore(&abort_suspend_lock, flags);
+}
+
/**
* wakeup_source_report_event - Report wakeup event using the given source.
* @ws: Wakeup source to report the event for.
@@ -590,8 +649,11 @@ static void wakeup_source_report_event(struct wakeup_source *ws, bool hard)
if (!ws->active)
wakeup_source_activate(ws);
- if (hard)
+ if (hard) {
+ if (pm_suspend_target_state != PM_SUSPEND_ON)
+ pm_abort_suspend_source_add(ws->name);
pm_system_wakeup();
+ }
}
/**
@@ -877,6 +939,7 @@ bool pm_wakeup_pending(void)
{
unsigned long flags;
bool ret = false;
+ struct pm_abort_suspend_source *info;
raw_spin_lock_irqsave(&events_lock, flags);
if (events_check_enabled) {
@@ -893,12 +956,29 @@ bool pm_wakeup_pending(void)
pm_print_active_wakeup_sources();
}
+ if (atomic_read(&pm_abort_suspend) > 0) {
+ raw_spin_lock_irqsave(&abort_suspend_lock, flags);
+ list_for_each_entry(info, &pm_abort_suspend_list, list) {
+ pm_pr_dbg("wakeup source or subsystem %s aborted suspend\n",
+ info->source_triggering_abort_suspend);
+ }
+ raw_spin_unlock_irqrestore(&abort_suspend_lock, flags);
+ }
+
return ret || atomic_read(&pm_abort_suspend) > 0;
}
EXPORT_SYMBOL_GPL(pm_wakeup_pending);
void pm_system_wakeup(void)
{
+ char buf[MAX_SUSPEND_ABORT_LEN];
+
+ if (pm_suspend_target_state != PM_SUSPEND_ON) {
+ sprintf(buf, "%ps", __builtin_return_address(0));
+ if (strcmp(buf, "pm_wakeup_ws_event"))
+ pm_abort_suspend_source_add(buf);
+ }
+
atomic_inc(&pm_abort_suspend);
s2idle_wake();
}
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index ef503088942d..2eef5817b825 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -528,6 +528,7 @@ extern void pm_print_active_wakeup_sources(void);
extern unsigned int lock_system_sleep(void);
extern void unlock_system_sleep(unsigned int);
+extern void abort_suspend_list_clear(void);
#else /* !CONFIG_PM_SLEEP */
@@ -556,6 +557,7 @@ static inline void pm_system_irq_wakeup(unsigned int irq_number) {}
static inline unsigned int lock_system_sleep(void) { return 0; }
static inline void unlock_system_sleep(unsigned int flags) {}
+static inline void abort_suspend_list_clear(void) {}
#endif /* !CONFIG_PM_SLEEP */
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index fa3bf161d13f..49c830246930 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -623,6 +623,7 @@ int pm_suspend(suspend_state_t state)
} else {
suspend_stats.success++;
}
+ abort_suspend_list_clear();
pr_info("suspend exit\n");
return error;
}
--
2.25.1