Bug 742817 - Battery life is cut in half on 2.6.40-4.fc15.x86_64 or higher
Summary: Battery life is cut in half on 2.6.40-4.fc15.x86_64 or higher
Status: CLOSED DUPLICATE of bug 727579
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 15
Hardware: x86_64
OS: Linux
Target Milestone: ---
Assignee: Kernel Maintainer List
QA Contact: Fedora Extras Quality Assurance
Depends On:
TreeView+ depends on / blocked
Reported: 2011-10-03 02:00 UTC by Jeremy
Modified: 2011-10-06 13:42 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2011-10-06 13:42:11 UTC

Attachments (Terms of Use)

Description Jeremy 2011-10-03 02:00:06 UTC
Description of problem:After updating from kernel- to kernel-2.6.40-4.fc15.x86_64, my battery life on a Lenovo X220 thinkpad went from 8 hours on a full charge to 4 hours. I can validate the longer battery life by booting on

Version-Release number of selected component (if applicable): 2.6.40-4.fc15

How reproducible: 100%

Steps to Reproduce:
1.Boot system with a fully charged battery on kernel-
2.Use system for ~8 hours on battery.
3.Boot system with a fully charged batter on kernel-2.6.20-4.fc15
4.Use system for only ~4 hours on battery.
Actual results:Battery life time is half of what it was on the older kernel.

Expected results: Same battery life time on newer kernels.

Additional info:I'm not sure what kind debug/log info would be needed to investigate. Let me know and I'll grab it.

Comment 1 Dave Jones 2011-10-03 15:45:32 UTC
Try adding i915.i915_enable_rc6=1 to your grub command line

Comment 2 Jeremy 2011-10-05 21:24:25 UTC
This has not helped my battery life. Occasionally I see the power indicator (in gnome-shell) show better time expected, but that usually only happens right after time of idle. Once I start using the system (terminal/ssh sessions -- SA work) it goes back down.

Comment 3 Jeremy 2011-10-06 13:42:11 UTC
found I had to add pcie_aspm=force to get back to batter usage I was used to. Found it in 727579

*** This bug has been marked as a duplicate of bug 727579 ***

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