When Sony announced their work on mainline Linux a year ago I was cautiously optimistic. Now a year on and it's great to see them collaborating with Jolla but I found this page which details current functionality on their open devices and I see that there is no mention of mainline kernel support, just old Android kernels. What concerns me is that the Xperia X has two kernels listed: 3.10 which is 3 years old and 3.18 which is 2 years old. 3.10 seems to be feature complete whilst 3.18 has a lot of hardware listed as WIP. That doesn't really inspire me with a lot of confidence in their mainline kernel support. A handful of N900 kernel hackers have achieved more than this in their spare time. Wake me up when Sony have a device which has mainline kernel support close to that of the N900.