Comment 4 for bug 1781533

New test kernel could be found here
http://people.canonical.com/~acelan/bugs/lp1779984/

0001-ata-ahci-Support-state-with-min-power-but-Partial-lo.patch
0002-ata-ahci-Enable-DEVSLP-by-default-on-x86-with-SLP_S0.patch
0003-ata-libahci-Correct-setting-of-DEVSLP-register.patch
0004-ata-libahci-Allow-reconfigure-of-DEVSLP-register.patch

We'll check if those commits help the power consumption.