This sort of thing can happen: root:~# echo default > /sys/module/pcie_aspm/parameters/policy -bash: echo: write error: Operation not permitted
For instance, the pmutils script normally installed at /usr/lib/pm- utils/power.d/pcie_aspm, which is executed on every change between mains and battery operation, can exhibit such behaviour. Even when pcie_aspm modes are offered the ability to set them may be disabled, and the pcie_aspm sysfs interface doesn't offer a way to tell that this is so. See http://smackerelofopinion.blogspot.co.uk/2011/03/making-sense-of- pcie-aspm.html for technical background on why setting the pcie_aspm mode might be disabled. In short "this behaviour is by design". -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1017746 Title: /sys/module/pcie_aspm/parameters/policy not settable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1017746/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs