Fedora 15 cut battery life in half!

[naticus]

So I just installed F15 and I really like it. I had to upgradde to kernel version 2.6.39.1 to get my wireless from disconnecting -- aparentlyey it is a bug in kernels 2.6.38.x .

Now my problem, and it was also a problem with kernel 2.6.38.x, is that my battery life on my netbook (gateway LT2320, atom n450 @1.6, gma 3150, 1gb ram, 1024x600) is cut by half. I used to get 7-8 hours of battery life, with Crunchbang, Ubuntu, etc., but now i get 4.5 hours.

I have read that this is a problem with the current kernels available after 2.6.37.x.

My question is have they found a fix? Are we going to have to wait for 2.6.31? How much longer until that kernel is in the fedora repositories?

Thanks in advance!

[xjonquilx]

Yes, a fix has been found! Unfortunately I don't know how to accomplish this myself, but the following article describes the fix: http://www.linuxfordevices.com/c/a/N...around/?kc=rss

[naticus]

I checked my policy and it was set to "powersave" but I beleive it needs to be on default. Not sure if I want to mess with this as it might make the system unresponsive.

how to check:

sys/module/pcie_aspm/parameters/policy

[stevea]

According to Phoronix ....

add "pcie_aspm=force" to their boot command line

This would go in the /boot/grub/grub.conf file, appended the the kernel line(s).

Phoronix has been spreading their typical alarmist-headlines + low-on-facts FUD about this problem for months. It is NOT a general problem AFAICT. It appears to be relate to a BIOS bug *some* systems.

In tests my Lenovo T510 is using slightly LESS power with 2.6.39.

[weitjong]

The Linux kernel power regression has been reported quite sometimes ago in Phoronix. Why not get the updates and possibly workaround directly from the source http://www.phoronix.com. Accurate or not, the NoScript plugin in my FF somehow does not *like* the site provided by URL above in the #2 post.

The way I understand it, the problem is with the Linux Kernel and although one of the culprit has been found, it seems it will still take some more time for the whole regression issue to be resolved and for the changes to propagate from upstream to Fedora Project, assuming the kernel developer will back port the fix at all.

In the latest Phoronix update on this issue, Larabel has provided a simple workaround by adding an option in the kernel option in the grub.conf. "pcie_aspm=force", but please read the article first. It is an interesting read.

---------- Post added at 09:44 PM ---------- Previous post was at 09:41 PM ----------

It looks like stevea beat me to it .

[naticus]

Originally Posted by weitjong

The Linux kernel power regression has been reported quite sometimes ago in Phoronix. Why not get the updates and possibly workaround directly from the source http://www.phoronix.com. Accurate or not, the NoScript plugin in my FF somehow does not *like* the site provided by URL above in the #2 post.

The way I understand it, the problem is with the Linux Kernel and although one of the culprit has been found, it seems it will still take some more time for the whole regression issue to be resolved and for the changes to propagate from upstream to Fedora Project, assuming the kernel developer will back port the fix at all.

In the latest Phoronix update on this issue, Larabel has provided a simple workaround by adding an option in the kernel option in the grub.conf. "pcie_aspm=force", but please read the article first. It is an interesting read.

---------- Post added at 09:44 PM ---------- Previous post was at 09:41 PM ----------

It looks like stevea beat me to it .

Logged in as root ( su --login) then I go to the file mentioned above and try to edit, but it says "I dont have permission necessary to open the file"

Is their another form of root I need to log into?

[xjonquilx]

Originally Posted by stevea

According to Phoronix ....

This would go in the /boot/grub/grub.conf file, appended the the kernel line(s).

Phoronix has been spreading their typical alarmist-headlines + low-on-facts FUD about this problem for months. It is NOT a general problem AFAICT. It appears to be relate to a BIOS bug *some* systems.

In tests my Lenovo T510 is using slightly LESS power with 2.6.39.

Thank you, I suspected it was Grub but wasn't sure.

---------- Post added at 10:33 AM ---------- Previous post was at 10:30 AM ----------

Originally Posted by naticus

Logged in as root ( su --login) then I go to the file mentioned above and try to edit, but it says "I dont have permission necessary to open the file"

Is their another form of root I need to log into?

Just log in to your regular user account and copy/paste the following in to Terminal:

sudo gedit /etc/grub.conf

It will ask for a password first, so type in your regular user password and press Enter. Gedit should pop up with the configuration without any issues. If you have problems, try this:

su

Type in the root password, then:

gedit /etc/grub.conf

I hope this helps!

[stevea]

sudo sed -e 's/ ro / ro pcie_aspm=force/' -i /etc/grub.conf

should do it.

[naticus]

Originally Posted by xjonquilx

Thank you, I suspected it was Grub but wasn't sure.

---------- Post added at 10:33 AM ---------- Previous post was at 10:30 AM ----------



Just log in to your regular user account and copy/paste the following in to Terminal:

sudo gedit /etc/grub.conf

It will ask for a password first, so type in your regular user password and press Enter. Gedit should pop up with the configuration without any issues. If you have problems, try this:

su

Type in the root password, then:

gedit /etc/grub.conf

I hope this helps!

Yep top line did the trick. Also the 'fix' aforementioned seemed to work. I got an extra 40% more battery life, and it got much closer to what I am used to (from abysmall 4hours to 7hours).

Now let's hope they can fix this in 2.6.31 kernel.

Thanks all for the help.

[marko]

Originally Posted by naticus

Yep top line did the trick. Also the 'fix' aforementioned seemed to work. I got an extra 40% more battery life, and it got much closer to what I am used to (from abysmall 4hours to 7hours).

Now let's hope they can fix this in 2.6.31 kernel.

Thanks all for the help.

2.6.31 is too old, it doesn't have this problem

[weitjong]

May be he meant kernel 3.1 instead

[naticus]

Originally Posted by weitjong

May be he meant kernel 3.1 instead

LOL that is correct. That is what 48 hour shift will do to you.

[PauGNU]

Originally Posted by stevea

sudo sed -e 's/ ro / ro pcie_aspm=force/' -i /etc/grub.conf

should do it.

Warning!!

We need a space! When I run this command, the result was:
<code>kernel /vmlinuz-2.6.38.8-32.fc15.x86_64 ro pcie_aspm=forceroot=/dev/mapper/VolGroup-lv_root rd_LVM_LV=VolGroup/lv_root</code>

As you can see, there was no space between «force» and «root».

[naticus]

So should their be a space? should I alter the config then? Or does it not matter?