Red Hat Bugzilla – Bug 142928
ACPI suspend to RAM consumes too much power
Last modified: 2015-01-04 17:13:56 EST
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Description of problem:
When I suspend to RAM on my ThinkPad T41, the suspended machine
remains warm to the touch. The battery is drained after 4-5 hours in
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Boot with ACPI for power management.
2. Suspend to RAM.
3. Wait a while.
Actual Results: Machine stays warm to touch. Battery drains after
Expected Results: Machine cools to room temp. Battery lasts in this
mode for several days.
In /etc/acpi/events, I have a file sleep.conf containing:
And in /etc/acpi/actions/sleep.sh, I have:
echo -n mem > /sys/power/state
APM suspend to RAM works just fine.
This bug is being tracked upstream at
but I thought it would be worth tracking here as well. I'm sure a
number of ThinkPad users are affected and would like to see the fix.
It's all that's keeping me from moving from APM to ACPI.
At http://bugzilla.kernel.org/show_bug.cgi?id=3022, they have
identified the main issue as failure of the radeonfb driver to suspend
the video chip. There are now patches posted there that solve the
problem for a number of models of Thinkpad.
The radeon D2, backlight patch is included in the latest development kernels
(the one i checked was kernel-2.6.11-1.1353_FC4) please test at let us know how
Please note, that for this to actually work, you'll need to have
"video=radeonfb" on your kernel command line.
Then rebuild your initrd with (remember backup if you'll be needing it) :
mkinitrd -f /boot/initrd-$(uname -r).img $(uname -r) --with=radeonfb
Also, if your machine is not explicitly enabled in the kernel code for this...
you need to invoke the force_sleep functionality of the module BEFORE doing the
in /etc/modprobe.conf put a line like this :
options radeonfb radeon_force_sleep=1
Hope this helps and works!
Can this package be built easily for FC3? I'd like to try it out, but I can't
afford to run test releases on this machine. I once tried rebuilding an FCn
kernel on FCn-1, but was utterly defeated by the dependencies.
Finally got to test this with kernel-2.6.11-1.1369_FC4 (FC4 release kernel).
AFAICT, it works very well. From my battery usage log:
Wed Jun 29 07:54:37 EDT 2005
before: 34660 mWh
after: 34060 mWh
diff: -600 mWh
seconds: 3555 sec
result: 607 mW
Congratulations, your model seems NOT to be affected.
600mW is probably still higher than it should be, but with the graphics chip
powered on the consuption is 4-5 times that.
Now if I could just have the penguin on the boot screen, my life would be
An update has been released for Fedora Core 3 (kernel-2.6.12-1.1372_FC3) which
may contain a fix for your problem. Please update to this new kernel, and
report whether or not it fixes your problem.
If you have updated to Fedora Core 4 since this bug was opened, and the problem
still occurs with the latest updates for that release, please change the version
field of this bug to 'fc4'.
Already updated to FC4 and so far the instructions from Comment #2 have worked
fine on all kernels through kernel-2.6.12-1.1398_FC4. It would be nice if the
setup happened automatically, though.
All the Fedora Thinkpad users I know are now on FC4, but we have some RHEL4
Thinkpad users. Will this patch be incorporated there?
for RHEL4, you'll need to file a seperate request.
I'm a fedora thinkpad user still on FC3 and the new kernel, with regards to the
power-saving, seems to work for me now.
However, on resume, i get this little problem
Back to C!
Debug: sleeping function called from invalid context at mm/slab.c:2126
This is on a IBM ThinkPad T30 (2366-JBG)
If I can provide you with more info, let me know!
If you'd like me to submit a seperate bug, let me know about that too.
Please file this as a seperate bug, thanks.