Comment 5 for bug 1829399

This is interesting.

`echo mem > /sys/power/state`
This command was instant S3. The screen went black and the power light
immediately began to blink.

However...for lid switch the power light takes around 10 seconds to begin
to pulse, but the state immediately switches.

Fri 17 May 2019 09:48:22 AM CEST - state: open
Fri 17 May 2019 09:48:23 AM CEST - state: open
Fri 17 May 2019 09:48:24 AM CEST - state: open
Fri 17 May 2019 09:48:25 AM CEST - state: closed
Fri 17 May 2019 09:48:26 AM CEST - state: closed
Fri 17 May 2019 09:48:27 AM CEST - state: closed

It seems although detection if immediate, it takes 10 seconds to process?

On Thu, May 16, 2019 at 6:05 PM Andrea Righi <email address hidden>
wrote:

> Hi Chris, just to make sure I understand (from a kernel perspective),
> can you confirm that `echo mem > /sys/power/state` is also fast at
> reaching the suspend state?
>
> In that case it would be interesting to check if there's a delay at
> detecting the state of the lid switch. For this, could you run the
> following command in a bash session:
>
> $ while :; do echo `date` - `cat /proc/acpi/button/lid/LID0/state`;
> sleep 1; done
>
> Close the lid, re-open it and you should notice something like this:
>
> Thu May 16 17:50:42 CEST 2019 - state: open
> Thu May 16 17:50:43 CEST 2019 - state: open
> Thu May 16 17:50:44 CEST 2019 - state: open
> Thu May 16 17:50:45 CEST 2019 - state: closed
> Thu May 16 17:50:46 CEST 2019 - state: closed
> Thu May 16 17:50:47 CEST 2019 - state: closed
> Thu May 16 17:50:48 CEST 2019 - state: open
> Thu May 16 17:50:49 CEST 2019 - state: open
> Thu May 16 17:50:50 CEST 2019 - state: open
> ^C
>
> Note that I have set the "lid close action" to do nothing, in this way
> we can better isolate the problem. Thanks.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1829399
>
> Title:
> Lid switch triggered suspend takes much longer than UI triggered
> suspend
>
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>

--

Chris Gregan
Engineering Manager
Solutions QA/Techops
<email address hidden>