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authorRajat Jain <rajatja@google.com>2017-10-31 14:44:24 -0700
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-11-08 23:52:02 +0100
commit95b982b45122c57da2ee0b46cce70775e1d987af (patch)
tree43598cf8b89db8c292043acec36d4732b99b9a6c /kernel/power
parent0e708fc602531b8355b5de6ea7c98f09129b223f (diff)
download96b-common-95b982b45122c57da2ee0b46cce70775e1d987af.tar.gz
PM / s2idle: Clear the events_check_enabled flag
Problem: This flag does not get cleared currently in the suspend or resume path in the following cases: * In case some driver's suspend routine returns an error. * Successful s2idle case * etc? Why is this a problem: What happens is that the next suspend attempt could fail even though the user did not enable the flag by writing to /sys/power/wakeup_count. This is 1 use case how the issue can be seen (but similar use case with driver suspend failure can be thought of): 1. Read /sys/power/wakeup_count 2. echo count > /sys/power/wakeup_count 3. echo freeze > /sys/power/wakeup_count 4. Let the system suspend, and wakeup the system using some wake source that calls pm_wakeup_event() e.g. power button or something. 5. Note that the combined wakeup count would be incremented due to the pm_wakeup_event() in the resume path. 6. After resuming the events_check_enabled flag is still set. At this point if the user attempts to freeze again (without writing to /sys/power/wakeup_count), the suspend would fail even though there has been no wake event since the past resume. Address that by clearing the flag just before a resume is completed, so that it is always cleared for the corner cases mentioned above. Signed-off-by: Rajat Jain <rajatja@google.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/suspend.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index ccd2d20e6b06..0685c4499431 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -437,7 +437,6 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
error = suspend_ops->enter(state);
trace_suspend_resume(TPS("machine_suspend"),
state, false);
- events_check_enabled = false;
} else if (*wakeup) {
error = -EBUSY;
}
@@ -582,6 +581,7 @@ static int enter_state(suspend_state_t state)
pm_restore_gfp_mask();
Finish:
+ events_check_enabled = false;
pm_pr_dbg("Finishing wakeup.\n");
suspend_finish();
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