If i with
dmesg | grep -i aspm
have this:
[ 0.503709] ACPI FADT declares the system doesn't support PCIe ASPM, so disable it
[ 0.673564] ACPI _OSC control for PCIe not granted, disabling ASPM
I've read that is a bug in the Linux kernel and I've also read that there is a workaround but I don't know if I have to apply this workaround or not.
So do I have to add pcie_aspm=force to grub2?
Ok, i've add "pcie_aspm=force" and i've gained 20 minutes :)
So if someone have a Sony Vaio VPC-EH1S0E can easily add the parameter to the grub line in this way:
sudo nano -w /etc/default/grub
and where there is this line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
change it into:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force"
You can also check the power consumption with powertop:
sudo apt-get install powertop
and then:
sudo powertop
My battery consumption was decreased from 20.1W to 15.3W :)
Andrew Wyatt's blog post About the Kernel 3.0 "Power Regression" Myth explains well about kernel regression and aspm issue. May be it would be of some help.
