In kernel v4.18 the major new feature is IR BPF.

IR decoding in BPF

Kernel v4.18 introduces a new type of BPF program, called BPF_PROG_LIRC_MODE2. This type of program can decode raw IR and report decoded scancodes. This is to support the many lircd.conf rc keymaps which are currently not supported by rc-core.

Now that the kernel space work is complete, ir-keytable needs to be extended to support BPF type decoders (loading, querying and deattaching) and we need a ne set of IR decoders. I’m currently working to this.

The ultimate goal is to support all the keymaps for IR decoding and sending that lircd currently supports, without the need to run a daemon.

Faster IR decoding

The in-kernel IR decoders have always been a little sluggish, since the timeouts they use are far greater than what is actually needed. So, now using IR is much more responsive and keys will less “sticky”. I think this makes a huge difference.

Other changes

There some other minor improvements, such a MCE Keyboard decoder improvements, and when a lirc device is registered, it reports if is has a transmitter and if it is a raw or scancode receiver (or no receiver at all).