On Tuesday 28 June 2011, Alan Cox wrote: > > (In fact, the correct thing to do would probably be to just do > > > > #define ENOIOCTLCMD ENOTTY > > > > and get rid of any translation - just giving ENOTTY a more appropriate > > name and less chance for confusion) > > Some code uses the two to separate 'the driver specific helper code > doesn't handle this' and 'does handle this'. In that situation you take > away the ability of a driver to override a midlayer ioctl with -ENOTTY to > say "I don't support this even if most people do" Right. Similarly, in compat_sys_ioctl returning -ENOIOCTLCMD from fops->compat_ioctl means "the driver has provided no compatibility handler for this command, need to check the global translation table", while -ENOTTY returned from ->compat_ioctl means "this command won't work on this device, don't bother looking at the table and don't print an annoying message". Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
