Re: [RFC] What are the goals for the architecture of an in-kernelIR system?

From: Maxim Levitsky
Date: Sun Nov 29 2009 - 12:28:52 EST


On Sun, 2009-11-29 at 12:40 +0000, Alan Cox wrote:
> > BTW, circa 1995 my serial mouse "Just Worked" in Linux. Sometime around
>
> Correct X11 just talked to the serial ports. In fact that is still the
> way to configure it if you want any sanity in life.
>
> > and serial connected IRs. It's also too convenient to access USB IR
> > hardware from existing userspace drivers to bother porting into the
> > kernel.
>
> Userspace needs a way to identify IR hardware and to interface with it
> using the right protocol. It's not clear the kernel needs to provide
> anything more than minimal hardware interfaces in most case - be that
> serial, libusb, ...

Exactly.
As it currently stands, kernel provides lircd the pulse/space timing,
lirc parses that, and sends input events via uinput.
lircd behaves just like an userspace driver, and the biggest advantage
is that it can access its configuration directly, unlike kernel solution
that will have to use some configfs hack.


It can use its own older interface, but that is now optional.
Also its not that hard to make lirc scan is database and adapt to the
remote that is used.
This should give the user absolutely zero configuration.

Instead, there is strong push to put lircd, the userspace daemon's
functionality into kernel.
This has zero advantages besides good developer feeling that "My system
has one less daemon..."

Best regards,
Maxim Levitsky

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