On Mon, May 17, 2021 at 01:35:09PM +0100, Sean Young wrote: > On Mon, May 17, 2021 at 11:35:22AM +0100, Sean Young wrote: > > On Mon, May 17, 2021 at 11:30:39AM +0200, Johan Hovold wrote: > > > Ok, but apart from BPF that sound like other stuff and not the three > > > items you list above? Is there anything preventing those items from > > > being implemented in user space? > > > > Well, after IR is decoded, you want to send decoded scancodes/key codes > > to any input device, so your remote works just like any input device. > > There is another advantage. IR decoding in userspace involves a lot more > context switches/scheduling, and it can feel laggy when the cpu is under > load (e.g. video decoding on the CPU). When you press pause/play/stop or > so you expect the response the instantatiously. A 100ms delay is noticable. RT scheduling? Sounds like you should be able to handle this way faster than 100 ms. > Alternatively the key-up events get delayed and you end up with multiple > un-intended button repeats. None of this happens with kernel decoding and > it feels very snappy. Yeah, perhaps it's best handled in-kernel, but it seems we should be able to handle a simple key press within 20 ms or whatever the critical latency is here using either option (kernel or user-space driver). Johan
