[systemd-devel] [WIP PATCH 0/4] Rework the unreliable LID switch exported by ACPI

[Bastien Nocera]

On Mon, 2017-06-19 at 01:43 +0000, Zheng, Lv wrote:
> <snip>
> > 
> > If you implement it in such a way that GNOME settings daemon
> > behaves weirdly, you'll get my revert
> > request in the mail. Do. Not. Ever. Lie.
> 
> First, I don't know what should be reverted...
> I have 2 solutions here for review, and Benjamin has 1.
> And none of them has been upstreamed.
> We are just discussing.

The discussion is getting tiring quite frankly. We've been over this
for nearly a year now, and with no end in sight.

> However we need to get 1 of them upstreamed in next cycle.
> 
> I think users won't startup gnome-setting-daemon right after resume.
> It should have already been started.
> 
> There is only 1 platform may see delayed state update after resume.
> Let's see if there is a practical issue.
> 1. Before suspend, the "lid state" is "close", and
> 2. After resume, the state might remain "close" for a while
>    Since libinput won't deliver close to userspace,
>    and gnome-setting-daemon listens to key switches, there is no
> wrong behavior.

It doesn't. It listens to UPower, which tells user-space whether there
is a lid switch, and whether it's opened or closed.

> 3. Then after several seconds, "open" arrives.
>    gnome-setting-daemon re-arrange monitors and screen layouts in
> response to the new event.

Just how is anyone supposed to know that there is an event coming?

> So there is no problem. IMO, there is no need to improve for post-
> resume case.
> 
> Users will just startup gnome-setting-daemon once after boot.
> And it's likely that when it is started, the state is correct.

You cannot rely on when gnome-settings-daemon will be started to make
*any* decision. Certainly not decisions on how the kernel should
behave.

> IMO, there might be a chance to improve for post-boot case using
> Benjamin's approach.