Re: [PATCH] make scsi_wait_scan always modular

[James Bottomley <James.Bottomley@SteelEye.com>]

On Sun, 2007-03-11 at 22:17 +0100, Guennadi Liakhovetski wrote:
> On Sun, 11 Mar 2007, James Bottomley wrote:
> > On Sun, 2007-03-11 at 21:56 +0100, Guennadi Liakhovetski wrote:
> > > Which means, with this change you cannot build a kernel without module 
> > > support but with scsi_wait_scan, which was possible before. Don't know if 
> > > anybody would ever want to do this though...
> > 
> > I'll do something about that if you can tell me how one might use
> > scsi_wait_scan without module support in the kernel ...
> 
> I won't:-) Just from the comment at the top of the patch I didn't get the 
> impression that this indeed was its intended result. Building statically 
> with scsi_wait_scan would mean that you might allow async scan, but then 
> some time at late_initcall() time you want a sync point. Could this ever 
> be desired? If not, just ignore my comment.

scsi_wait_scan is designed to be a module that is loaded *after* you've
loaded all HBA modules that doesn't return from module_init until the
scans previously launched by the HBA module insertions are complete.  In
a monolithic kernel, this is done by the async scan infrastructure but
in a modular kernel, you have to have some signal that you've finished
loading the SCSI modules (which is what scsi_wait_scan is).

So, if you build a kernel without module support, ipso facto you have no
SCSI modules to load and therefore you can't have a use for
scsi_wait_scan.

James