I tested 3.13.0.51.44 version of linux-image-generic-lts-trusty package on Ubuntu Precise 12.04.5 (which contains trusty kernel backports).
And looks like it working fine. See log: $ lspci -nn | grep 00:1c.7 00:1c.7 PCI bridge [0604]: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #8 [8086:8c1e] (rev d4) $ sudo lspci -s 00:1c.7 -v -v | grep -i aspm LnkCap: Port #8, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <1us, L1 <16us LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk- $ cat /sys/bus/pci/devices/0000:00:1c.7/power/link_state 0 $ echo 1 | sudo tee /sys/bus/pci/devices/0000:00:1c.7/power/link_state 1 $ sudo lspci -s 00:1c.7 -v -v | grep -i aspm LnkCap: Port #8, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <1us, L1 <16us LnkCtl: ASPM L0s Enabled; RCB 64 bytes Disabled- Retrain- CommClk- $ echo 2 | sudo tee /sys/bus/pci/devices/0000:00:1c.7/power/link_state 2 $ sudo lspci -s 00:1c.7 -v -v | grep -i aspm LnkCap: Port #8, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <1us, L1 <16us LnkCtl: ASPM L1 Enabled; RCB 64 bytes Disabled- Retrain- CommClk- $ echo 3 | sudo tee /sys/bus/pci/devices/0000:00:1c.7/power/link_state 3 $ sudo lspci -s 00:1c.7 -v -v | grep -i aspm LnkCap: Port #8, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <1us, L1 <16us LnkCtl: ASPM L0s L1 Enabled; RCB 64 bytes Disabled- Retrain- CommClk- $ echo 0 | sudo tee /sys/bus/pci/devices/0000:00:1c.7/power/link_state 0 $ sudo lspci -s 00:1c.7 -v -v | grep -i aspm LnkCap: Port #8, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <1us, L1 <16us LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk- tag verification-done-trusty tag -verification-needed-trusty -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1398544 Title: Please enable CONFIG_PCIEASPM_DEBUG To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1398544/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs