Description of problem:After updating from kernel-220.127.116.11-35.fc15.x86_64 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 18.104.22.168-35.f15.
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-22.214.171.124-35.fc15
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.
Try adding i915.i915_enable_rc6=1 to your grub command line
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.
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 ***