Re: RFC: Harmonised parameter passing

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, 8 Mar 2005 15:59:23 +0100, Henk Vergonet
<rememberme@god.dyndns.org> wrote:
> 
> Hi,
> 
> The current method of parameter passing to drivers build as a module is extremely usefull.
> Modules don't have to write there own parsing code, there's a nice macro that can be used to document specifics of the parameter and so on.
> 
> Could we extend this method where we use the same methodology for inbound drivers? (Currently a lot of drivers use their own parameter parsing code when it comes to passing values at kernel boot time.)
> 
> so we could do the regular:
> 
>        insmod mcd io=0x340
> 
> for modules, or with kernel boot parameters:
> 
>        mcd.io=0x340
> 
> for in-kernel drivers.
> 

Umm.. This is already done. For parameters defined with module_param()
you use <paramname>=<value> for modules and
<modulename>.<paramname>=<value> for built-in case.

> My proposal would be to introduce something like:
> 
> DRIVER_PARM_DESC(variable, description);
> DRIVER_PARM(variable, type, scope);
> 
>    where scope can be:
>        PARM_SCOPE_MODULE       => This parameter is used in module context.
>        PARM_SCOPE_KERNEL       => This parameter is used in kernel context.
>        PARM_SCOPE_MODULE | PARM_SCOPE_KERNEL
>                                => This parameter is used in both kernel and module context, which should be the default if scope is omitted.
> 

Why would you want parameters that only work for modules? I'd consider
it a bug, not a feature, when parameter works only when code is
modularized.

-- 
Dmitry