Re: Implementing ALSA compatibility in OSS

[Takashi Iwai <tiwai@suse.de>]

At Mon, 15 Nov 2004 19:31:23 +0200 (EET),
Hannu Savolainen wrote:
> 
> On Mon, 15 Nov 2004, Jaroslav Kysela wrote:
> 
> > On Mon, 15 Nov 2004, Hannu Savolainen wrote:
> >
> > > OSS is a driver API and it's definitely designed to be used directly.
> >
> > It's (and was) a broken idea. We have never ending trouble to reroute your
> > API to ours, because you have not designed a proper library in the user
> > space to handle application requests.
> Interesting point. Do you mean that all Linux drivers for whatever devices
> should have defined their own library interface instead of the using the
> traditional Unix device/file interface?

It depends.  Accessing to the device file would make sense for many
simple devices, but not for the devices with wide variety.

The problem of the direct device access is that it restricts the
extension of the API.  It can never exceed the limitation of the
kernel.  That is, you can't use floating point in the lowlevel
(i.e. system level) layer.


> To me this uniform and robust device/file abstraction was the main reason
> to get married with Unix. That happened exactly 20 years ago, btw. It was
> also the reason why I originally designed OSS in this way.
> 
> OSS doesn't have it's own library API. Our goal has been to develop  as
> good device drivers as possible and nothing else. As a small company have
> intentionally left all user space development (including libraries) to
> others.

I see your point.  I would say it's a different design decision.

For example, the current design of ALSA lib isn't well suitable for
the embedded system.  It's because we wanted to have a powerful and
extensible middle layer which can be used uniquely by apps.  For the
tiny systems, OTOH, it's too bold.


Takashi


-------------------------------------------------------
This SF.Net email is sponsored by: InterSystems CACHE
FREE OODBMS DOWNLOAD - A multidimensional database that combines
robust object and relational technologies, making it a perfect match
for Java, C++,COM, XML, ODBC and JDBC. www.intersystems.com/match8