Bug 115141 - power consumption suspend2ram ACPI/APM
Summary: power consumption suspend2ram ACPI/APM
Status: RESOLVED WONTFIX
Alias: None
Product: SUSE LINUX 10.0
Classification: openSUSE
Component: Mobile Devices (show other bugs)
Version: Beta 4
Hardware: x86 SUSE Other
: P5 - None : Enhancement
Target Milestone: ---
Assignee: Holger Macht
QA Contact: E-mail List
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2005-09-03 14:59 UTC by m. bracher
Modified: 2005-11-28 10:40 UTC (History)
4 users (show)

See Also:
Found By: Other
Services Priority:
Business Priority:
Blocker: ---
Marketing QA Status: ---
IT Deployment: ---

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description m. bracher 2005-09-03 14:59:57 UTC 
Hardware: Laptop IBM T40 - Type 2373-92G
Software: SuSE 10 Beta4, Beta3 or Suse9.3

suspend2disk works with acpi and apm
suspend2ram works with apm
suspend2ram works with acpi, but the suspend state is not what I expect. 

Suspended2ram with acpi, the laptop consumes approx. 8-10 Watt, that means, when
you resume the laptop after some hours, the battery life is extremely reduced...
Suspend with apm only uses 1-2 Watt.
With acpi, Display is dark, fan and harddisk is stopped, but the network card is
still active and the light of the DVD-drive is on.

I don't know if you can reproduce the problem and have a solution. When not, APM
works fine, but unfortunately the information in /proc/acpi is not available.
Comment 1 Vojtech Pavlik 2005-09-03 15:24:43 UTC 
This is a known problem, and one not easily fixed. It means going over every
device, every driver, every laptop and figuring how to power it down. Usually
ACPI methods work, sometimes PCI sleep states, sometime per-device magic.

Often, we don't know even how to turn the backlight off when in suspend-to-ram.

We'll get there, but definitely not in time for 10.0.
Comment 2 m. bracher 2005-09-04 11:21:45 UTC 
No problem, let me know when you need additional information. 

Some weeks ago, I installed Suse9.3 on a T40 and the newer T42. It seems that
this ACPI problem does not occur on T42.

PS: Backlight is not the problem here, it is off :-)
Comment 3 Stefan Behlert 2005-09-29 13:07:33 UTC 
Re-open to assign it to the correct developer for tracking
Comment 4 Stefan Behlert 2005-09-29 13:09:29 UTC 
Holger: We should look at that again after run-time power management
Comment 5 Holger Macht 2005-09-29 13:34:26 UTC 
Yes, I already thought about this issue.
Comment 6 Holger Macht 2005-09-29 13:37:57 UTC 
Lowering severity because this is some kind of feature request.
Comment 7 Lenz Grimmer 2005-11-11 17:53:56 UTC 
http://thinkwiki.org/wiki/Problem_with_high_power_drain_in_ACPI_sleep has some more background info about this problem, too.
Comment 8 Holger Macht 2005-11-28 10:40:13 UTC 
Nice page. But I think we cannot help with the high power drain during suspend to ram. All pci devices are powered down by default by the kernel on suspend, thus doing it manually before suspend won't help. The bugreport caring about this problem can be found at http://bugme.osdl.org/show_bug.cgi?id=3022. Sorry, but I have to close the bug as WONTFIX.