on_ac_power script returns 255 during boot

[Erik de Castro Lopo]

Binary package hint: powermgmt-base

Machine is a Dell Latittude X1 running Dapper with a stock 2.6.15-23-686 kernel.

When booting on battery power, the on_ac_power script fails with an error code of 255. This has the result of allowing fsck's to occur during bootup on battey which is undesirable.

[Robert Collins (lifeless)]

I've confirmed this. My guess is that acpid is not up with the right modules when the checkfs/checkrootfs calls occur... mjg59 confirms this - the battery and ac modules need to be loaded for this script to work.

[Matthew Garrett (mjg59)]

Modules need to be loaded earlier

[Erik de Castro Lopo (erikd)]

A colleague of mine (Peter Miller) went to the trouble of debugging this further.

He found that by adding:

        battery
        ac
        sbs

to the file /etc/initramfs-tools/modules and then running the command:

        sudo update-initramfs -u

fixed the problem on his laptop.

I tried the same fix on my laptop and tested it by using tune2fs to temporarily set the max-mount-counts to 2 and then rebooted the machine a couple of times to verify.

Considering this is such an easy fix, it would be nice if this could be rolled into an existing package (say laptop-detect or laptop-mode-tools) or as part of the installation procedure.

[Loïc Minier (lool)]

/sbin/on_ac_power is in powermgmt-base, so I'm reassigning this bug over there.

Of course the easiest and fastest case is to build the modules in the kernel; that's the case in jaunty but doesn't help hardy nor custom kernels.

On my system, the aforementioned modules are loaded automatically during boot even when not specified in /etc/default/acpid, so it's probably just a race that on_ac_power needs the modules loaded. I think on_ac_power could be improved to test for ACPI support and modprobe the relevant modules if the information is not present yet (just like we load modules to find the rootfs).

[Rolf Leggewie (r0lf)]

Hardy has seen the end of its life and is no longer receiving any updates. Marking the Hardy task for this ticket as "Won't Fix".