Just in case others are having battery life problems with laptops installing tuned an tuned-profiles-compat on the laptop, and putting this script in the /etc/pm/power.d directory makes a big difference in battery life.
As tuned upstream I recommend you not to use the tuned-profiles-compat. It is there for backward compatibility. It's better to use the powersave profile from the base package. Currently the laptop-battery-powersave is just an alias to powersave profile but we would like to phase it out. In tuned version 2 we wanted to simplify the profiles and use the best approach regardless of the machine type by utilizing auto-detection etc. I.e. we wanted the powersave profile to mean the max power-savings always.
#!/bin/sh # 00-powermodes case $1 in true) tuned-adm profile laptop-battery-powersave ;; false) tuned-adm profile balanced ;; *) echo "ERROR: used incorrectly." ;; esac
This is something we wanted to ship in the past, but we stepped back as this may be not the best option for all users. Sometimes doing the job quickly on the full computational power and then sleeping/idling may save more energy (time on battery) in total than doing the same job on throttled machine. That's why the balanced profile which incorporates dynamic switching/balancing between performance/powersave may fit better. But the script above may help in case your laptop is mostly idling when on the battery (e.g. it is mostly used for internet browsing when mobile). For such use case scenarios the script may be useful.
As well I had a suspend and resume problem with the backlight on my Dell XPS 13 (Intel GMA 4000).. after a suspend and resume, the backlight would could not be adjusted, and was set to max brightness.
The user space workaround/scripts are temporal hacks. Please report the issues to Red Hat Bugzilla [1] against component kernel, because they are all kernel bugs that needs to be fixed.
Hope this will save people a lot of googling. Is this something that could be submitted to the developers as patch?
Thanks for sharing. It would be great if you could start a wiki page for your laptop model and to add the workarounds/bugzilas links to the wiki so other people could benefit from it. I think such page could be freely created on fedoraproject wiki and it would be also great to link it from Fedora Hardware Compatibility List [2]
thanks & regards
Jaroslav
[1] http//bugzilla.redhat.com/enter_bug.cgi [2] http://fedoraproject.org/wiki/HCL/Machines/Laptops