On Thursday 30 October 2014 12:02:39 Tom Gundersen wrote: > On Thu, Oct 30, 2014 at 9:20 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > I think in general, using enum is great, but for ioctl command numbers, > > we probably want to have defines so the user space implementation can > > use #ifdef to see if the kernel version that it is being built for > > knows a particular command. > > Does that make sense for the first version? I agree that we should use > #define to allow #ifdef for when we add more ioctls in the future, > but these ioctls will always exist... It's mainly for consistency really. > The nice thing about enums is of course that it helps with debugging > as gdb can show the string representation rather than the number, > because in contrast to #defines, an enum is something the compliler > knows about. This doesn't get passed as an enum in user space though, and when debugging the kernel it only helps within one function. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html