Comment 10 for bug 1398544

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