After some more extensive testing I cannot confirm the regression anymore on my Panasonic CF-T5: forcing pcie_aspm and manually setting powersave:
echo powersave > /sys/module/pcie_aspm/parameters/policy solves the problem for me as well. >From /proc/cpuinfo: vendor_id : GenuineIntel cpu family : 6 model : 14 model name : Genuine Intel(R) CPU U1400 @ 1.20GHz I made a script for pm-powersave, attached as pcie_aspm, and put it in /etc/pm/power.d I made a table to summarize the results of the tests, reporting powertop results on 4 hours Wakeups/s (lower=better), C3% (perc. of time in higest C state, higher=better), PLow% (perc. of time at lowest CPU freq, higher=better), battery duration (hh:mm, based on battery-stats log), avg temperatures of the two available sensors (estimate based on collectd graphs). All tests were run with screen brightness 10/21, dpms on (switching off the screen after 10min), wifi off (in normal conditions the battery lasts less then half the times obtained in the tests, but it's still pretty good). Kernel | Wakeups/s | C3% | PLow% | Power | Battery | Temp0 C | Temp1 C | 2.6.35-28.50 +aspm 50.7 93.6 77.0 5.8W 15:15 38 39 2.6.38-11.50 +aspm 53.7 94.4 81.8 4.0W 16:23 37 38 2.6.38-12.51 +aspm a 47.2 94.1 84.6 8.7W 8:57 38 42 2.6.38-12.51 +aspm b 46.1 93.2 70.2 4.8W 14:52 38 39 The thing I realized running the tests is that acpi estimate of battery state (and power) is not so reliable, therefore I had very different results with when starting the tests as soon as the charge was 100%, and when it was left powered for a few hours while at 100%. That was the only difference among the two runs with 2.6.38-12.51, marked a and b in the table. As you can see, repeating the test after some time with the ac adapter plugged in gave me results which are comparable to maverick. Thanks a lot to all contributors to this very long bug report! ** Attachment added: "pm-powersave script to enable/disable pcie_aspm powersave" https://bugs.launchpad.net/ubuntu-release-notes/+bug/760131/+attachment/2585219/+files/pcie_aspm -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/760131 Title: Power consumption raised significantly in natty To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-release-notes/+bug/760131/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
