On Tue, Apr 23, 2019 at 05:23:14PM +0200, laurent vaudoit wrote: > > Be in sync with mainline is usually best choice at start of project > > and probably not so good choice at start of production. > > i totally agree with this. > i've started looking more, and what i've seen is that the actual j1939 > (from can-next) is based on can version 20170425 It doesn't matter what "old" version it was based; the stack has been completely reworked for mainline inclusion. So the stack is currently for top-of-tree and you can use it with Linux 5.1 (or maybe backport with some effort to 5.0 or even 4.19). > and the kernel we plan to use is based on 20120528 (kernel V4.9. > 88), so i'm wondering how difficult this can be to use the let's say > "futur mainline"j1939 stack on this kernel. Can you elaborate why you want to use such an old kernel for a current project? While 4.9 has longterm status, there is no reason at all to use it for new projects. Even if you aim for LTS (note that LTS has only a value if you are prepared to continuously update to the latest dot releases of the LTS series), you should start with 4.19, not with 4.9. If you are interested in a more in-deep discussion, you might want to read https://www.pengutronix.de/en/blog/2018-08-28-what_kernel_to_use.html > Except if there is some wor allready done on this base version? Why? rsc -- Pengutronix e.K. | Dipl.-Ing. Robert Schwebel | Industrial Linux Solutions | https://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
