[ltp] Re: [ibm-acpi-devel] cannot resume after hotplugging an ultrabay battery in Z61p

[Marc MERLIN]

On Fri, Feb 20, 2009 at 11:38:59PM -0300, Henrique de Moraes Holschuh wrote:
> On Mon, 16 Feb 2009, Marc MERLIN wrote:
> > Were you able to find any config options that don't look good to you?
> 
> Sorry, no :(  But you have some heavy duty debugging stuff that you should
> disable if you don't use them, like kprobes.  I'd also disable cgroup and
> the group scheduler if you don't use them.
 
I've turned them off and built 2.6.28.7. We'll see...
 
> > Similarly, I have a nagging but annoying problem where my laptop will
> > occasionally hard deadlock when I plug the power back in while it was
> > running on batteries.
> 
> If you are using either nVidia or ATI proprietary drivers (sorry, I forgot
> the details), they react to power management events like AC
> connected/disconnected, and so I suppose a bug there might cause hangs.  If
> it is a hard-to-hit race, the hangs would not happen very often.

Yes, I know about them. Luckily I'm now able to run standard kernel ATI dri
and Xorg drivers.

> I don't think the open drivers do this (i.e. they're not advanced enough for
> that yet :p), though.  Maybe Intel's do, they're big on the PM stuff.  The

They have no hooks, but the open source drivers seem to take less power than
the ATI ones did, even with the PM clock throttling stuff.

> X.org server also wants to listen to acpi events nowadays (and does so,
> probably through HAL), so it gets difficult to know for sure what might be
> reacting to the AC connected event and causing a hang.

Since I have a recent X.org I think it does that internally indeed, and I'm
really wondering if they are linked.

> It could also be the BIOS fighting X.org.  Try telling the BIOS to not touch
> the screen brightness level when you plug/unplug AC, and see if that stops
> the hangs...

Ah, good tip. I'll try that.

> > I just upgraded to 2.6.28.4 so we'll see what happens, but if you have
> > recommendations on kernel options, debugging, or other ideas, I'm all ears.
> > (like can I debug on usb serial, or do I need real serial?)
> 
> There is a hideous hack to log data to the RTC (will scramble the time,
> though, so it is not good if you cannot reproduce the problem easily as you
> cannot really have that thing enabled all the time) that does work almost
> always.
 
Ah, yes, I read about that. I'll have to try that to reproduce the battery
hang.
 
Thanks for the tips,
Marc
-- 
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Home page: http://marc.merlins.org/