elogind-service specifies a variable that's ignored by defualt

"HandleLidSwitchExternalPower= is completely ignored by default (for backwards compatibility)"[1]

I noticed (with help in IRC) that my laptop wasn't suspending on lid close when plugged in and charging, which I hadn't seen happen on other systems. I now know that I can set this by configuring the `elogind-service` parameter `handle-lid-switch-external-power`. Regardless, it seems like it should default to being unset rather than set/ignored, since that would heed the line I quoted above.

[1]: https://www.freedesktop.org/software/systemd/man/logind.conf.html

Am Sonntag, dem 07.08.2022 um 23:29 +0000 schrieb Cairn:

I think you're misreading that line. What it states is not that

"HandleLidSwitchExternalPower" is ignored by default, but

"HandleLidSwitchExternalPower=" is ignored by default, i.e. there will

be no value unless one was provided (whichever semantics "no value" has

later on) is only confusingly explained later on.

IMHO the Guix behaviour of always setting a value is the right one

(explicit is better than implicit after all). As for the default

values, one might disagree as to which fits, but I don't think ignoring

lid switches while powered is harmful.

Cheers

Hi Liliana,

On +2022-08-08 12:45:10 +0200, Liliana Marie Prikler wrote:

What would you advise if there's no battery power,

or for some reason one is running on plug power only,

for worriers that the bulding power might fail?

I'd guess a power brick would power for some milliseconds

and wonder if this is detectable, i.e., to do something

at least to leave a goodbye world message somewhere if the machine

was not suspended with sufficient state to resume after power restore?

Buy a UPS, and don't go away long enough for that to run out? :)

--

Regards,

Bengt Richter

Am Dienstag, dem 09.08.2022 um 03:52 +0200 schrieb bokr@bokr.com:

I do think that we're starting to split hairs here, but for the sake of

the argument, elogind should be able to detect whether or not the power

supply it's attached to actually delivers power. If your laptop

doesn't have a battery, then pulling the plug on it has the same

effects as pulling the plug on a regular PC, there's nothing you can do

in elogind to make that a safe action.

Cheers

(Resending this email, since I forgot to add the debugs.gnu.org address as a recipient)

That's fair!

Well, if explicitly setting variables is the standard, then I suggest changing `handle-lid-switch-external-power` to the same value as `handle-lid-switch` ("suspend"). I agree that the current setting isn't harmful, but this change would match the default, unconfigured behavior of `elogind`. It would also be more consistent with other distros' defaults from what I've experienced.

Hi,

Liliana Marie Prikler <liliana.prikler@ist.tugraz.at> writes:

It can be. I have a Lenovo T430s with a partially discolored LCD from

heat after I left it closed in a backpack for a couple hours, thinking

it would have suspend (it was not). That would not have happened with

the value supposed to be default (which matches the behavior used on

most other systems).

So I'd favor having the default to suspend on any lid close.

Thanks,

Maxim

Hi,

Maxim Cournoyer <maxim.cournoyer@gmail.com> writes:

For the record, this was noticed and discussed more than a year ago, see

Message-ID: <871rens9a2.fsf@nckx>. It had fallen into the cracks, it

seems.

Maxim

LOL. I'm the one who asked Cairn to report this. I didn't remember publicly reporting it, I only remembered noticing it and not fixing it, and didn't want it to get forgotten 'again'. Sorry for the noise!

Strongly disagree that the current Guix behaviour makes any sense, let alone better! That sounds like posthockholm rationalisation to me. If people want opinionated variants, those can be written on top of a service that properly exposes upstream behaviour.

Kind regards,

T G-R

Sent on the go. Excuse or enjoy my brevity.

Would it not still be explicit if variables that should go unspecified were written out, but not given a value? Maybe I'm misunderstanding the point of explicit values though.

Hello,

Cairn <cairn@pm.me> writes:

I made it *unspecified* in 59ee837d8b, given this service config doesn't

yet use 'define-configuration' that would have allowed for a proper

maybe-value.

Tested to work on a X200 and pushed!

Closing, at last.

Thanks,

Maxim