Possible to implement battery charge threshold on {Free,Net,Open}BSD?
reddit / BSD

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[deleted] · 2019-10-07 19:38

[deleted]

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Ottaviocr · 2019-10-07 19:39



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ZarK-eh · 2019-10-07 20:31

Is Tip only for thinkpads?

While distro hopping, power management on a laptop is pretty important
as well as servers. A server will run longer during battery only
events. My windows laptops and servers get power options tweaks (power
button is on/off, low and critical battery levels raised).
On my freenas and opensense installs expose powerd simplistic control
and I wants MOAH! ... too

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Ottaviocr · 2019-10-07 21:07



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SaturnFive · 2019-10-07 21:52

One could take a look at `sysctl hw.sensors` if the hardware supports
it and write a wrapper around it do to different things based on the
values. On my system I have various `hw.sensors.acpibat0` values for
displaying the max and current battery capacity and an AC power
indicator.

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Ottaviocr · 2019-10-08 07:49



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liveoneggs · 2019-10-08 12:02

"no demand" so "netbsd won't do it" doesn't seem to add up ;)

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Ottaviocr · 2019-10-08 17:13



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sehnsuchtbsd · 2019-10-08 19:12

What is it you're exactly looking for? NetBSD's
[powerd(8)](https://netbsd.gw.com/cgi-bin/man-cgi?powerd+8+NetBSD-
current) allows an acceptable degree of tinkering and customization
through a series of event  [scripts](http://cvsweb.netbsd.org/bsdweb.c
gi/src/etc/powerd/scripts/?only_with_tag=MAIN), similarly to Linux
acpid

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Ottaviocr · 2019-10-08 19:30

I'm pretty sure one could hack the sensor_battery script to make
something out of it. I'm not sure powerd exposes the battery charge
levels or it can activate them. I'll have to ask that on irc tomorrow.

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sehnsuchtbsd · 2019-10-08 21:04

>  I'm not sure powerd exposes the battery charge level

[envstat(8)](https://netbsd.gw.com/cgi-bin/man-cgi?envstat+8+NetBSD-
current) does; check also [envsys(4)](https://netbsd.gw.com/cgi-
bin/man-cgi?envsys+4+NetBSD-current) ;

I use envstat to generate battery charge lebel indicators for conky,
tint2, etc...

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Ottaviocr · 2019-10-08 21:28

but can you then manipulate these indicators and set a range of
battery level charges? Let's say: charge between 50 and 60%? As long
as I understand, envsys can only indicate overcharging and high-
capacity.

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sehnsuchtbsd · 2019-10-09 04:31

definitely, you're right here: I was rather thinking about using the
envsys framework as an acpi abstraction layer for any powerd script
you'd have potentially created ;)

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linrunner · 2019-10-13 17:33

ThinkPads (beginning with the \*20 generation) provide a distinct set
of ACPI calls for (1) thresholds and force\_discharge (2). On Linux
(1) has been implemented in the thinkpad\_acpi kernel driver, the
corresponding patches which contain the calls are listed [here](https:
//github.com/linrunner/TLP/issues/321#issuecomment-379813611).

For (2) – and also (1) – there is an older user space implementation
called [tpacpi-bat](https://github.com/teleshoes/tpacpi-bat) using a
[generic kernel driver](https://github.com/teleshoes/acpi_call) to
issue the same ACPI calls. tpacpi-bat may also serve as a reference.

So the task seems to implement said ACPI calls in the BSD kernel.

Hope it helps.

ps. i'm TLP's author.

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Ottaviocr · 2019-10-15 10:22

Thanks. I was going to ask that on Github. I'll feedback that to the
NetBSD kernel hackers.