On Thu, Apr 27, 2017 at 10:34:18PM +0200, David Härdeman wrote: > Using the full 32 bits for all kinds of NEC scancodes simplifies rc-core > and the nec decoder without any loss of functionality. At the same time > it ensures that scancodes for NEC16/NEC24/NEC32 do not overlap and > removes lots of duplication (as you can see from the patch, the same NEC > disambiguation logic is contained in several different drivers). > > Using NEC32 also removes ambiguity. For example, consider these two NEC > messages: > NEC16 message to address 0x05, command 0x03 > NEC24 message to address 0x0005, command 0x03 > > They'll both have scancode 0x00000503, and there's no way to tell which > message was received.
It's not ambiguous, the protocol is different (RC_TYPE_NEC vs RC_TYPE_NECX). > In order to maintain backwards compatibility, some heuristics are added > in rc-main.c to convert scancodes to NEC32 as necessary when userspace > adds entries to the keytable using the regular input ioctls. These > heuristics are essentially the same as the ones that are currently in > drivers/media/rc/img-ir/img-ir-nec.c (which are rendered unecessary > with this patch). There are issues with the patch which breaks userspace, as discussed in the previous patch. None of those issues have been addressed. In addition, I've read https://david.hardeman.nu/rccore/#problems-nec There is nothing there what you have not stated before about nec being "ambiguous", even though the protocol variant is different. Sean
