On Sun, 14 Jan 2001, Linus Torvalds wrote:
> This is what "request_module()" and "kmod" is all about. Once we probe the
> hardware, the drievr itself can ask for more drivers.
>
> I completely fail to see the arguments that have been brought up for drm
> doing ugly things. The code should simply do
>
> drm_agp_head_t * head = inter_module_get("drm_agp");
>
> if (!head) {
> request_module("drm-agp");
> head = inter_module_get("drm_agp");
> if (!head)
> return -ENOAGP;
> }
>
> and be done with it. THE ABOVE MAKES SENSE. The code says _exactly_ what
> the module wants to do: it wants to find the AGP support, and if it cannot
> find the AGP support it wants to load them.
It's the same with CFI command-set-specific code. Except that the
command-set specific code didn't previously have to be initialised at all,
and now we've got to initialise it (and have it call
inter_module_register) before it's required by the cfi_probe code.
The difference here is that while drm_agp actually had to do some hardware
initialisation, the CFI command set handlers didn't - the only thing their
module_init routine does is call inter_module_register(). So we've
introduced the init order dependencies where previously they weren't
necessary.
That's the one flaw in the inter_module_get() stuff - we could do with a
way to put entries in the table at _compile_ time, rather than _only_ at
run time.
While I accept that we can't eliminate init order dependencies completely,
I still think we should avoid them where it's possible. Which it would be
in this case, without much difficulty at all.
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This archive was generated by hypermail 2b29 : Mon Jan 15 2001 - 21:00:39 EST