[mythtv-users] lirc_serial move to serial_ir nightmare in kernel 4.12

[Tom Dexter]

On Tue, Aug 22, 2017 at 3:38 PM, Alec Leamas <leamas.alec at gmail.com> wrote:
>
>
> On 22/08/17 21:26, Tom Dexter wrote:
>>
>> On Tue, Aug 22, 2017 at 2:48 PM, Alec Leamas <leamas.alec at gmail.com>
>> wrote:
>>>
>>>
>>> You have noted that here are two paths, right? One which uses the kernel
>>> decoding (ir-lirc-codec etc), an event device and the devinput driver.
>>> And
>>> one bypassing the kernel decoding, using the /dev/lirc0 device and the
>>> default driver? And that the latter part requires that the kernel
>>> decoding
>>> is disabled i. e., that only the lirc protocol is enabled in the
>>> /sys/class/rc/rc0 device?
>>>
>>>
>>> Cheers!
>>>
>>> --alec
>>
>>
>> Wow...I'm a bit confused, but this may be the whole issue. If you're
>> saying that the latter...that is the use of /dev/lirc0 and the default
>> driver...should NOT be using ir-lirc-codec at all, and should be
>> bypassing the kernel decoding, then that's clearly my problem right
>> there. However it brings up the other issue I mentioned in the first
>> post:
>>
>> When I first enabled serial_ir in the kernel (IR_SERIAL, which I
>> enabled built in, and not as a module), I didn't get ANY /dev/lirc0
>> device at all. The only way I could get it to create /dev/lirc0 was by
>> enabling IR_LIRC_CODEC, which seemed odd. If I'm understanding what
>> you're saying correctly, then that was clearly a mistake. However I'd
>> also need to know why I'd get no /dev/lirc0 with SERIAL_IR enabled
>> directly in the kernel.
>>
>> OGM...I think I may have just figured it out. I probably shouldn't
>> have RC_DECODERS enabled at all should I. Would that prevent
>> /dev/lirc0 from getting created without enabling a decoder?
>
>
>
> This is basically an internal kernel/driver issue above my paygrade. IIRC,
> most drivers actually create the /dev/lircX device when loaded, but only
> send data to it if the lirc protocol is enabled in
> /sys/class/rc/rc0/protocols.
>
> When so, the other protocols should be disabled - if not for other reasons,
> anything decoded by the kernel is just a pain when using the lircd decoding.
>
>
>
> Cheers!
> --alec

Maybe you cat at least clear me up as to what I actually should have
enabled in the kernel, as I'm more confused than ever looking at the
config options:

Here's what I have:

grep LIRC .config
CONFIG_LIRC=y
# CONFIG_IR_LIRC_CODEC is not set

grep IR_SERIAL .config
CONFIG_IR_SERIAL=y
# CONFIG_IR_SERIAL_TRANSMITTER is not set

grep RC_SUPPORT .config
CONFIG_MEDIA_RC_SUPPORT=y

Do you now of anything else I should need?

With that however I still get no /dev/lirc0 device. It's possible that
could be somehow related to the fact that I have it built into the
kernel. At least I'm clear that using CONFIG_IR_LIRC_CODEC was totally
wrong in this case.

Tom