Re: CVS commit: src/sys/dev

[Masao Uebayashi <uebayasi%gmail.com@localhost>]

On Mon, Nov 3, 2014 at 9:49 PM, Quentin Garnier <cube%cubidou.net@localhost> wrote:
> On Sat, Nov 01, 2014 at 07:54:18AM +0000, Masao Uebayashi wrote:
>> Module Name:  src
>> Committed By: uebayasi
>> Date:         Sat Nov  1 07:54:18 UTC 2014
>>
>> Modified Files:
>>       src/sys/dev: audio.c audio_if.h
>>
>> Log Message:
>> Revert previous.
>>
>> Not only audio_attach_mi() but also audioprint() have to be separated.
>> midi.c has the same problem, and a little more complicated.  These will be
>> revisited later.
>
> It's because they are functions for "audiobus" (where audio(4) attaches)
> rather than for "audio".  So you can split them into a file that depends
> on audiobus.

Understood.

Let me reprase: "audiobus" is already an interface attribute.  Those
functions (audio_attach_mi(), audioprint(), ...) will belong to
audiobus.c (or .o, or .ko).  Those drivers providing the "audiobus"
interface (e.g. auich(4)) will depend on audiobus module.  So:

        device auich: audiobus, ...

The funny thing here is, the line has two meaning: a) providing
"audiobus" interface, b) depending on "audiobus" module.  Due to the
limitation of the config(5) syntax!

One question is, when to unload audiobus-as-a-module.  It is depended
on by audio if drivers, but it does not depend on anything.  When all
audio if drivers are unloaded, there is not reason to keep it in
kernel.  Maybe some (smart) ref-counting is needed.

> Most pseudo-buses have that issue I think.  Probably some actual buses
> too.  I'd not really expect a kernel that has pchb but not pci selected
> to compile.

I've not really looked into pseudos yet...