On Fri 2015-05-29 13:36:09, Theodore Ts'o wrote: > On Fri, May 29, 2015 at 05:01:00PM +0200, Richard Weinberger wrote: > > On Fri, May 29, 2015 at 4:53 PM, Enrico Weigelt, metux IT consult > > <weigelt@xxxxxxxx> wrote: > > > Am 29.05.2015 um 04:54 schrieb Luis R. Rodriguez: > > > Actually, I really wonder why folks are sticking to ancient kernels on > > > newer hardware. > > > > Enterprise distribution kernels. Or "special" kernels like PREEMPT_RT. > > Sometimes the vendor BSP is that horrid that a customer cannot afford > > to forward port it > > but wants recent stuff. So you need to backport... > > Yep. The technique I used for the backporting ext4 encryption into > the 3.10 android-common git tree in AOSP was to drop in the 3.18 > versions of fs/ext4 and fs/jbd2 into the 3.10 tree (along with the > associaed include files in include/linux and include/trace/events, of > course), and then fix things up until they built correctly (using > cherry-picks and in some cases, reverting some changes in the 3.18 > version of fs/ext4). After I was sure the transplant of the 3.18 > version of ext4 had "taken" correctly, with no test regressions, only > then did I cherry-pick all of the ext4 encryption changes on top of > 3.10. > > The backport of ext4 encryption to the 3.18 version of android-common > should be much easier. :-) Unfortunately, I also have to do a > backport to the 3.14 android-common branch as well. <sigh> > > Yes, it's ugly, but there still are some SOC and drivers that aren't > available on newer kernels. Basically, the handset vendors need to > lean a lot harder on the SOC and other peripheral (cell radios, GPS, > etc., etc.). :-( Actually, what we really want is chip vendors to clean up the interfaces, and merge their changes upstream... Perhaps we'll be able to install normal distros on cellphones one day... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe backports" in
