[ltp] T40p Crashing

[Ramon Casellas]

On Tue, 23 Sep 2003, John Goerzen wrote:

> Hello,
>
> I have been running 2.4.21-ac1 on my T40p for quite some time with
> very good success.  However, I have been having trouble with newer
> kernels.

Hi,

According to my personal experience (and some mails from people having
similar problems, from acpi.sf.net and lkml) here's what I would say :
it's not the best moment to play around with 2.6.0 + Power Management +
Thinkpads, they do not mix very well...Yet! Of course, this may only apply
to some models, or maybe I've been particularly clumsy, but,

Basically, unless you have a good reason (and regarding only power
management!) stick with a well tested 2.4.2X + APM. I'm usually using
2.6.0, but that's because in some aspects 2.6.0 is really better, but not
power management.


There are some issues :

* APM/ACPI: According to some reports, kernel-2.4.21-acX was quite stable
in this sense (ACPI or APM). Thinkpad users (including myself) were able
to suspend to mem/disk without problems. I was using APM, and "default"
bios. APM worked fine for most kernel versions. Lots of thinkpads users
are using 2.4.21,22... with success (APM)

* ACPI: Later kernels 2.4.22 - 23pre3 IIRC (which include ACPI
versions previous to the very latest one, 20030916), did not work with
newer thinkpads (or with older if you happened to have a particular newer
BIOS version). This was the quite common AE_TIME error,...ACPI was
unusable for these versions.

* With 2.6.X, power management in general is quite broken.  There was
quite an important patch for 2.6.0-test3 that changed the power management
code. Some has been reverted to a previous state.APM is not in good shape,
the changes in the device driver model have made some components
(regarding power management again) somewhat buggy. ACPI is ... in
progress. Recent kernels (2.6.0-test5-mm3/mm4) bring the latest patches
Pavel Machek/Patrick Mochel and things are promising, but still not there.
Nowadays, you may be able to user power management features with some
"tricks" like unloading USB modules, switching to a console,etc...

* Moreover, if using APM, with 2.6.X tpctl thinkpad modules do not compile
(for example, if you are using devfs). The author has plans of updating
it, as soon as he finds some time...

* ACPI : kernels 2.4.22 - 2.6/0-test5 before 2.6.0-test5-bk8 IIRC need
external patches in order to correctly detect the embedded controller
found in recent thinkpads. <2.6.0-test5-mm4 need another patch (see
acpi-devel mailing list or lkml). this is a well known issue, reported by
Ruben Puettman in osdl.

* Finally, I would like to know if someone has been succesful in using
ACPI with 2.6.0-testX, not only being able to check the contents of
/proc/acpi and for interrumpt management, but also being able to suspend
to mem/disk.



>
> * 2.4.22-ac3 crashes when I hit Fn-F3 to turn off the screen.

I don't know exactly what it may be. There has been a thread recently.


> * 2.6.0-test5 crashes on boot when compiled with ACPI.

Use mm3 or mm4, there are some patches (regarding IRQ routing, if you get
something lile "calculating ACPI/IRQ penalities; or lots of debug messages
BAT0...) this is the kernel I'm using.


Do not get me wrong. These coders are doing and excellent work, and I
don't want to sound like a just-a-user-complaining. I know the "here's the
code, code it yourself" motto, but I'm just sharing my experiences...


Best regards,
R.