This allows active suspend blockers to be listed
Signed-off-by: Arve Hjønnevåg <arve@xxxxxxxxxxx>--- include/linux/suspend_block.h | 5 ++- kernel/power/suspend_block.c | 77 ++++++++++++++++++++++++++++------------ 2 files changed, 58 insertions(+), 24 deletions(-)
diff --git a/include/linux/suspend_block.h b/include/linux/suspend_block.hindex 7820c60..73ac5f7 100755--- a/include/linux/suspend_block.h+++ b/include/linux/suspend_block.h@@ -16,12 +16,15 @@ #ifndef _LINUX_SUSPEND_BLOCK_H #define _LINUX_SUSPEND_BLOCK_H +#include <linux/list.h>+ /* A suspend_blocker prevents the system from entering suspend when active. */ struct suspend_blocker { #ifdef CONFIG_SUSPEND_BLOCK- atomic_t flags;+ struct list_head link;+ int flags; const char *name; #endif };diff --git a/kernel/power/suspend_block.c b/kernel/power/suspend_block.cindex b4f2191..697f52a 100644--- a/kernel/power/suspend_block.c+++ b/kernel/power/suspend_block.c@@ -33,19 +33,29 @@ 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 atomic_t suspend_block_count;-static atomic_t current_event_num;+static LIST_HEAD(inactive_blockers);+static LIST_HEAD(active_blockers);+static int current_event_num; struct workqueue_struct *suspend_work_queue; struct suspend_blocker main_suspend_blocker; static suspend_state_t requested_suspend_state = PM_SUSPEND_MEM; static bool enable_suspend_blockers; +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);+}+ bool suspend_is_blocked(void) { if (WARN_ONCE(!enable_suspend_blockers, "ignoring suspend blockers\n")) return 0;- return !!atomic_read(&suspend_block_count);+ return !list_empty(&active_blockers); } static void suspend_worker(struct work_struct *work)@@ -62,7 +72,7 @@ retry: goto abort; } - entry_event_num = atomic_read(¤t_event_num);+ entry_event_num = current_event_num; if (debug_mask & DEBUG_SUSPEND) pr_info("suspend: enter suspend\n"); ret = pm_suspend(requested_suspend_state);@@ -76,7 +86,7 @@ retry: tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec); }- if (atomic_read(¤t_event_num) == entry_event_num) {+ if (current_event_num == entry_event_num) { if (debug_mask & DEBUG_SUSPEND) pr_info("suspend: pm_suspend returned with no event\n"); goto retry;@@ -110,6 +120,8 @@ static struct sys_device suspend_block_sysdev = { */ void suspend_blocker_init(struct suspend_blocker *blocker, const char *name) {+ unsigned long irqflags = 0;+ if (name) blocker->name = name; BUG_ON(!blocker->name);@@ -117,7 +129,12 @@ void suspend_blocker_init(struct suspend_blocker *blocker, const char *name) if (debug_mask & DEBUG_SUSPEND_BLOCKER) pr_info("suspend_blocker_init name=%s\n", blocker->name); - atomic_set(&blocker->flags, SB_INITIALIZED);+ 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); @@ -127,15 +144,15 @@ EXPORT_SYMBOL(suspend_blocker_init); */ void suspend_blocker_destroy(struct suspend_blocker *blocker) {- int flags;+ unsigned long irqflags; if (debug_mask & DEBUG_SUSPEND_BLOCKER) pr_info("suspend_blocker_destroy name=%s\n", blocker->name);- flags = atomic_xchg(&blocker->flags, 0);- WARN(!(flags & SB_INITIALIZED), "suspend_blocker_destroy called on "- "uninitialized suspend_blocker\n");- if (flags == (SB_INITIALIZED | SB_ACTIVE))- if (atomic_dec_and_test(&suspend_block_count))- queue_work(suspend_work_queue, &suspend_work);+ 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(suspend_work_queue, &suspend_work);+ spin_unlock_irqrestore(&list_lock, irqflags); } EXPORT_SYMBOL(suspend_blocker_destroy); @@ -145,15 +162,19 @@ EXPORT_SYMBOL(suspend_blocker_destroy); */ void suspend_block(struct suspend_blocker *blocker) {- BUG_ON(!(atomic_read(&blocker->flags) & SB_INITIALIZED));+ unsigned long irqflags;++ spin_lock_irqsave(&list_lock, irqflags);+ BUG_ON(!(blocker->flags & SB_INITIALIZED)); + blocker->flags |= SB_ACTIVE;+ list_del(&blocker->link); if (debug_mask & DEBUG_SUSPEND_BLOCKER) pr_info("suspend_block: %s\n", blocker->name);- if (atomic_cmpxchg(&blocker->flags, SB_INITIALIZED,- SB_INITIALIZED | SB_ACTIVE) == SB_INITIALIZED)- atomic_inc(&suspend_block_count);+ list_add(&blocker->link, &active_blockers); - atomic_inc(¤t_event_num);+ current_event_num++;+ spin_unlock_irqrestore(&list_lock, irqflags); } EXPORT_SYMBOL(suspend_block); @@ -165,13 +186,23 @@ EXPORT_SYMBOL(suspend_block); */ void suspend_unblock(struct suspend_blocker *blocker) {+ unsigned long irqflags;++ spin_lock_irqsave(&list_lock, irqflags);+ if (debug_mask & DEBUG_SUSPEND_BLOCKER) pr_info("suspend_unblock: %s\n", blocker->name);+ list_del(&blocker->link);+ list_add(&blocker->link, &inactive_blockers); - if (atomic_cmpxchg(&blocker->flags, SB_INITIALIZED | SB_ACTIVE,- SB_INITIALIZED) == (SB_INITIALIZED | SB_ACTIVE))- if (atomic_dec_and_test(&suspend_block_count))- queue_work(suspend_work_queue, &suspend_work);+ if ((blocker->flags & SB_ACTIVE) && list_empty(&active_blockers))+ queue_work(suspend_work_queue, &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); @@ -181,7 +212,7 @@ EXPORT_SYMBOL(suspend_unblock); */ bool is_blocking_suspend(struct suspend_blocker *blocker) {- return !!(atomic_read(&blocker->flags) & SB_ACTIVE);+ return !!(blocker->flags & SB_ACTIVE); } EXPORT_SYMBOL(is_blocking_suspend); -- 1.6.1
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