3 ms·
Believe it or not, there is a very small number of keyboards that use custom USB 3.0 controllers purely for isosynchronous mode, to get "PS/2 port interrupt"-li
by DiabloD3 7y ago
Believe it or not, there is a very small number of keyboards that use custom USB 3.0 controllers purely for isosynchronous mode, to get "PS/2 port interrupt"-like behavior.
However, if you have a modern USB 2.0 "gaming keyboard controller" polling at 1000ms, who cares. Job done, go home.
- rasz 7y agoDo you mean Endpoint Ready (ERDY)? That is only available for non-isochronous endpoints.
- monocasa 7y agoNo, I think they're just constantly streaming out updates over a custom isochronous endpoint so the driver doesn't have to go out and request it at all like you do even with ERDY.
- rasz 7y agoWouldnt that swamp CPU with interrupts?
- monocasa 7y agoI mean, as much as a USB microphone does. That'd be isochronous too, and about the same bitrate and latency.
- amluto 7y agoThat would be awful for a keyboard. With sound, either the CPU wakes up to process sound very frequently or it processed sound in big chunks with high latency. Neither choice is reasonable for a keyboard.
- monocasa 7y agoIf you're the kind of person that gets that keyboard, you don't really care about power consumption on your CPU. Handling it as it's streamed in really isn't that big of a deal. It's not even like sound where you'd be doing a bunch of DSP on it right after.