Subject: Re: status of mpc52xx with arch=powerpc?

From: Benjamin Herrenschmidt <[email-masked]>
Date: Sat, 28 Oct 2006 08:39:25 +1000

> We would use the API we worked earlier on (Dale, Andrey, John, ...).
> To add support of fw preloaded task :
>  - The bestcomm.ko module would be used when bestcomm is completely
> controlled by the kernel
> - A different module but with the same exported function would be used
> when the fw has a part to play in the init. That allows to customize a bunch
> of the sdma init / sram mapping ...
> - All the other code (task helpers / the .h / the driver api) would be
> exactly
> the same.

No. Two different modules is the wrong approach. I want to be able to
build everything in the kernel (no modules) and still boot machines with
both types.

There should be a single implementation. I know bestcomm is fucked by
design but still.

> So the bestcomm modules maintain a list with all task loaded with a name and
> a index attribute. (The index would be used when there is multiple
> device with
> the same name, like "psc". We could use names like "psc1", "psc2". But that
> would imply string manipulation to "create" the name string ;)
> 
> In the case of the "classic" (kernel handles it all), the table of task
> is just
> initially empty. But for the "custom" case, it's filled with whatever
> the fw has
> passed as infos.

A single module should handle all cases though. If, for some reasons, it
looks like that will cause a lot of additional code, them it can be
internally split and we can have config options to enable only one way,
but it should be possible to enable both.

Ben.