false battery alarm with realtime app running (jackd)
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
gnome-power-manager (Ubuntu) |
Incomplete
|
Low
|
Unassigned |
Bug Description
Binary package hint: gnome-power-manager
When I have the JACK daemon running with realtime priority on this MSI Wind U100 laptop and pull out the wall power, the system tells me that the battery is low and enters hibernation. The battery is full, though.
If JACK is not active, nothing happens (just the battery symbol goes gray, which is irritating, but intended, I guess).
This forced hibernation is particulary annoying as JACK really does not like going to sleep; it cannot be killed by an ordinary user after resume (meaning: stop it via the button in qjackctl); pkill -9 jackd is needed. But that's another bug in the JACK audio server that one could live with, wouldn't the system -- and I suspect it's called gnome-power-manager here -- force a suspend to disk.
I'll check again if it's really just an issue when JACK has realtime priority, after posting this initial report (don't wanna loose it as collateral damage). Even if it is, I suspect some nasty race condition that could occur any time, but is helped by the scheduling schism introduced by JACK.
ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: gnome-power-manager 2.32.0-0ubuntu1
ProcVersionSign
Uname: Linux 2.6.35-22-generic i686
Architecture: i386
Date: Sun Oct 24 09:43:17 2010
GnomeSessionIdl
GnomeSessionInh
GnomeSessionSus
MachineType: MICRO-STAR INTERNATIONAL CO., LTD U90/U100
ProcCmdLine: root=UUID=
ProcEnviron:
LANG=de_DE.utf8
SHELL=/bin/bash
SourcePackage: gnome-power-manager
dmi.bios.date: 12/01/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 4.6.3
dmi.board.
dmi.board.name: U90/U100
dmi.board.vendor: MICRO-STAR INTERNATIONAL CO., LTD
dmi.board.version: Ver.001
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: MICRO-STAR INTERNATIONAL CO., LTD
dmi.chassis.
dmi.modalias: dmi:bvnAmerican
dmi.product.name: U90/U100
dmi.product.
dmi.sys.vendor: MICRO-STAR INTERNATIONAL CO., LTD
OK, scrap the thing about JACK. It must have been luck before, but now I was able to get the forced hibernation without jackd running at all. The rather infurinating thing is that I get dialog that tells about the fact and offers "OK" and "Cancel" buttons... which have no effect on the action being taken. It might be nice if "Cancel" being pressed withing some time frame would cancel the hibernation process. I even triggered multiple hibernations in a row (unplug, plug, unplug). Causing the laptop to go to sleep again right after waking up.
Anyhow: When unplugging from wall power, I get this notification blended onto the desktop about battery state ... and it tells me about 0:02 of battery runtime, 99% .. which somewhat contradicts the information when clicking on the battery applet, there I get 99%, OK, but also the much more sensible estimated runtime of 1:59 or so.
Still, this seems to be a timing issue, perhaps the ACPI information doesn't change atomically, or there is just an error in the runtime calculation using an outdated value of whatnot. I suspect, that this might be worked around by waiting some seconds and then recomputing the remaining runtime -- and only triggering the emergency if the situation is confirmed.
I do wonder though, if nobody else can reproduce this. Is the MSI Wind U100 BIOS just broken? I'm remined of the strange issues with the webcam and USB, or the Bluetooth/WLAN switch not working correctly by chance (gladly, it works in the Maverick install, as opposed to the live system from USB).