Automatic shutdown with devd.

[David DEMELIER]

2010/6/1 Ian Smith <smithi at nimnet.asn.au>:
> In freebsd-questions Digest, Vol 313, Issue 4, Message: 26
> On Tue, 1 Jun 2010 10:55:08 +0200 David DEMELIER <demelier.david at gmail.com> wrote:
>
>  > I recently asked to make an automatic shutdown when I excess a
>  > specific percent. I ran devd with -Dd flags to run in background and
>  > when the battery was at a critical state it said :
>  >
>  > Processing event '!system=ACPI subsystem=CMBAT type=\_SB_.BAT0 notify=0x80'
>  > Pushing table
>  > setting system=ACPI
>  > setting subsystem=CMBAT
>  > setting type=\_SB_.BAT0
>  > setting notify=0x80
>
> You should be aware that notify 0x80 for CMBAT indicates 'BST' or
> Battery State Change; you'll get these on shifting to any new state.
>
> You can check the new state with 'sysctl -n hw.acpi.battery.state'.
> 'acpiconf -i0' shows a translation between state masks and names.
>
>  > Then I tried (for testing) something like this in my /etc/devd.conf
>  >
>  > notify 10 {
>  >         match "system"          "ACPI";
>  >         match "subsystem"       "CMBAT";
>  >         match "notify"          "0x80";
>  >         action "logger LETGOSHUTDOWN";
>  > };
>  >
>  > And then I can see the following output in /var/log/messages :
>  >
>  > Jun  1 10:48:54 Melon power_profile: changed to 'performance'
>
> Reflecting your AC line state changing from Battery to AC.  devd.conf
> and /etc/rc.d/power_profile have good clues for handling devd notifies.
>
>  > Jun  1 10:48:56 Melon root: LETGOSHUTDOWN
>  > Jun  1 10:49:12 Melon root: LETGOSHUTDOWN
>  > Jun  1 10:51:06 Melon last message repeated 2 times
>  >
>  > It works, but the problem is that it makes this even the cable is
>  > plugged ! i.e : the computer was not powered on so with 3% of
>  > remaining time but AC plugged in after booting it (always with the AC
>  > plugged in) these messages appears too. I guess the ACPI/CMBAT do not
>  > care if there is an AC plugged in or not.
>
> See /sys/dev/acpica/acpi_cmbat.c for the gory details.
>
> Yes, ACAD and CMBAT are independent subsystems, so rather than an inline
> action like "logger .." here, you might follow the examples to run your
> own script, passing the notify to that (if you may also want to check
> for notify 0x81, BIF battery info changes, though these occur rarely)
>

So I will check deeper.

>  > Is there a way to make this conditional to do only if the laptop is
>  > not charging, AC plugged in ?
>
> Your script can check whether the AC power is on with:
>
>        AC=`sysctl -n hw.acpi.acline`
>        if [ $AC = 1 ]; then
>                exit 0          # or whatever, when on AC power
>        elif [ $AC = 0 ]; then
>                :               # do whatever when on battery
>        else
>                :               # AC/Battery state unknown ..
>        fi
>
> You could try just logging all state changes for a while; from critical
> charging to charging to high to discharging to critical discharging, I
> think that's the lot .. you can also check hw.acpi.battery.life etc.
>

Okay I will try a script like this one.

> However, your system should do an 'emergency suspend' on critical low
> battery anyway .. usually set at 1% capacity but some BIOS will let you
> adjust that (see acpiconf -i0).  Only if suspend/resume works of course.
>

It would be great if suspend/resume would works yes ! For the moment
it's not the case :

http://www.freebsd.org/cgi/query-pr.cgi?pr=i386/146715

Thanks for your answer ;-)

-- 
Demelier David