Krzysztof Halasa wrote:

Mauro Carvalho Chehab [off-list ref] writes:

quoted

If you use a kfifo to store the event (space_or_mark, timestamp), 
the IRQ handler can return immediately, and a separate kernel thread 
can do the decode without needing to touch at the IRQ.

But the decoding itself is a really simple thing, why complicate it?
There is no need for the kernel thread if the handler is fast (and it
is).

The decoding of just one protocol may be fast, but having several decoders
serialized (without kthreads, you're serializing the decoders) will possibly
not be that fast.

Also, you don't need wake the decoders kthreads for every event, but wait
for some number of events to happen before waking it. For example,
16 pulse/space events correspond to 8 bits of data on most protocols, 
so you can wake the kthread only after 16 events for really simple decoders,
or if a timeout event is detected. The number of events to wake may be customized
per decoder.

Cheers,
Mauro.