Sorry, please ignore, sent by mistake.
On Thu, May 10, 2018 at 4:34 PM, Rajat Jain <[email protected]> wrote: > 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. > > What this patch does: > > It moves the clearing of the flag to just before a resume is completed, > so that it is always cleared for the corner cases mentioned above. > > Signed-off-by: Rajat Jain <[email protected]> > --- > kernel/power/suspend.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > 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(); > Unlock: > -- > 2.15.0.403.gc27cc4dac6-goog >
