On Mon, Jul 29, 2013 at 1:31 AM, Maxime Ripard <maxime.rip...@free-electrons.com> wrote: > Hi, > > On Sun, Jul 28, 2013 at 03:19:03PM +0200, Richard Cochran wrote: >> On Sun, Jul 28, 2013 at 11:12:53AM +0200, Tomasz Figa wrote: >> >> > I'm not really sure what effect on users this has. Maybe you should define >> > "users". >> >> ... >> >> > Care to explain this reasoning? >> >> Use Case >> ~~~~~~~~ >> >> User acquires a machine running ARM Linux version 3.x, with u-boot >> and dtb in a read only flash partition. The board boots and works just >> fine. However, for his application, the user requires a new kernel >> feature that appeared in version 3.y where y > x. He compiles the new >> kernel, and it also works. > > I'm afraid this kind of use case will never be properly supported, DT > stable ABI or not.
Why? New kernel features should be no problem at all. New driver features /might/ not be available, but only if the new feature requires additional data that isn't present in the tree and cannot be obtained elsewhere. > > Think about this: what kernel will actually be shipped in that board? > Most likely, it will be a BSP kernel from the vendor. Does the vendor > will have made that commitment to have a stable ABI for the DT? Will it > use the same bindings than mainline? Do we want to support all the crazy > bindings every vendor will come up with? That's not a DT issue. That an out-of-tree board/SoC support issue. DT doesn't make that any better or worse. g. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/