Bug 742817

Summary:	Battery life is cut in half on 2.6.40-4.fc15.x86_64 or higher
Product:	[Fedora] Fedora	Reporter:	Jeremy <jerlyon>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED DUPLICATE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	15	CC:	gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-10-06 13:42:11 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Jeremy 2011-10-03 02:00:06 UTC

Description of problem:After updating from kernel-2.6.38.8-35.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 2.6.38.8-35.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-2.6.38.8-35.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.

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 ***