**WARNING: MAKE SURE THAT ALL PCIe HARDWARE IN YOUR SYSTEM SUPPORTS ACTIVE-STATE POWER MANAGEMENT**

- If you have seen a battery drain increase since the .38 kernel, it is very likely due to this reason, however double-check because applying this fix to older hardware that does not support ASPM may cause the system to stop responding.

Originally found here:

 http://www.phoronix.com/scan.php?page=article&item=linux_2638_aspm&num=1

This fixes the most prominent of the Linux kernel power regressions. This has plagued users since the .38 kernel, and caused much larger than normal power drain on portable devices. I do not recommend applying this fix to desktops because it will increase latency, however for laptops/netbooks/etc it makes a noticable difference. If (and ONLY if) you have seen a battery life reduction when upgrading to the .38 kernel, apply the fix as follows:

1) Edit GRUB

- Type this into the terminal:

gksudo gedit /etc/default/grub

- Go to the line GRUB_CMDLINE_LINUX=""

- Change it to GRUB_CMDLINE_LINUX="pcie_aspm=force"

- Save and exit

2) Update GRUB

- Type this into terminal:

sudo update-grub

3) Shut down and then power back on

- Once you do a full shutdown and then power it back on to access GRUB again, the fix will apply itself

I noticed an immediate jump in battery life after applying the fix:

- Laptop = 2hr45min to 3hr20min

- Netbook = 4hr45min to 6hr40min (!!!!!)

It seems to have greater impact on Atheros wireless cards than Broadcom, but it will increase it substantially nonetheless.

**NOTE**

- This will increase latency (not problematic, but basically don't apply it where you don't need to, like to a desktop)

- This does NOT fix other power regressions existing in the kernel, such as the one from the .35 migration.

- I'm NOT the person who created this fix, so I can't really answer questions about it. I'm just the awesome dude who shared it. ;)

Enjoy!