Re: [PATCH] PM / Sleep: Print last wakeup source on failed wakeup_count write
From: Rafael J. Wysocki
Date: Tue Jun 11 2013 - 17:51:19 EST
On Thursday, May 30, 2013 01:02:17 PM Julius Werner wrote:
> Commit a938da06 introduced a useful little log message to tell
> users/debuggers which wakeup source aborted a suspend. However, this
> message is only printed if the abort happens during the in-kernel
> suspend path (after writing /sys/power/state).
>
> The full specification of the /sys/power/wakeup_count facility allows
> user-space power managers to double-check if wakeups have already
> happened before it actually tries to suspend (e.g. while it was running
> user-space pre-suspend hooks), by writing the last known wakeup_count
> value to /sys/power/wakeup_count. This patch changes the sysfs handler
> for that node to also print said log message if that write fails, so
> that we can figure out the offending wakeup source for both kinds of
> suspend aborts.
>
> Signed-off-by: Julius Werner <jwerner@xxxxxxxxxxxx>
> ---
> drivers/base/power/wakeup.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> index 79715e7..b0b7886 100644
> --- a/drivers/base/power/wakeup.c
> +++ b/drivers/base/power/wakeup.c
> @@ -772,6 +772,8 @@ bool pm_save_wakeup_count(unsigned int count)
> events_check_enabled = true;
> }
> spin_unlock_irqrestore(&events_lock, flags);
> + if (!events_check_enabled)
> + print_active_wakeup_sources();
This is going to be done in the autosleep case too, which I'm slightly
concerned about.
If you wanted to cover /sys/power/wakeup_count only, it would be better
to put that into wakeup_count_store(), but perhaps you wanted to cover
autosleep too?
> return events_check_enabled;
> }
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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