On Wed, May 20, 2015 at 09:21:16AM +0200, Linus Walleij wrote: > On Tue, May 19, 2015 at 5:39 PM, Johan Hovold <johan@xxxxxxxxxx> wrote: > > On Tue, May 19, 2015 at 04:12:35PM +0200, Linus Walleij wrote: > > >> What? If I wanted a stable interface I would use sysfs and document > >> the ABI in Documentation/ABI/*. > >> > >> debugfs is not ABI. > > > > As I mentioned in my response to Grygorii, not everyone -- and most > > notably apparently not even Linus Torvalds -- agrees on this: > > Yeah I was sloppy I guess. > > What I mean, precisely is that sysfs is ABI, whether documented or > not. > > Even debugfs is actually blurry, as per > Documentation/filesystems/debugfs.txt: > > "The debugfs filesystem is also intended to not serve as a stable > ABI to user space; in theory, there are no stability constraints placed on > files exported there. The real world is not always so simple, though [1]; > even debugfs interfaces are best designed with the idea that they will need > to be maintained forever." > > But I haven't been bitten by it yet so that's why I allow some poetic > license. Yes, and the [1] reference in that quote is the LWN article I referred to. I also see you already "broke" that ABI in a similar way in 2013 with d468bf9ecaab ("gpio: add API to be strict about GPIO IRQ usage") by adding the IRQ field. Your call. :) Johan -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html