Re: [ndctl PATCH 2/2] libdaxctl: fix device reconfiguration with builtin drivers

["Verma, Vishal L" <vishal.l.verma-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Wed, 2019-09-04 at 14:01 -0700, Dan Williams wrote:
> On Wed, Sep 4, 2019 at 1:27 PM Verma, Vishal L <vishal.l.verma-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
> > On Tue, 2019-09-03 at 19:20 -0700, Dan Williams wrote:
> > > 
> > > Hmm, why wait until now to check if this list is NULL. How about fall
> > > back to kmod_module_new_from_name() at to_module_list() time? That
> > > would seem to simplify this follow up routine to not need to worry
> > > about working around a NULL list.
> > 
> > So we moved the list checking to later in the process around v4 of the
> > original series, so that we don't unnecessarily fail add_dax_dev() if
> > for some reason a list wasn't created.
> 
> Ah true, I forgot that wrinkle, however...
> 
> > Also, we use mod_name = dax_modules[mode] during an 'enable' to
> > determine the module name to use for the fallback - we wouldn't have
> > this at add_dax_dev() time.
> 
> Since modalias is already not reliable it seems the implementation
> should go ahead never do module lookups and just do everything based
> on module names.
> 
> In other words the libndctl panacea of not needing to hard code module
> names is already lost in libdaxctl land. If the code drops modalias
> usage does that clean up some of these flows?

Yep I think so - we use modalias to construct a lookup list, but we
still have to use the name to resolve to the final module based on the
mode. I think we can remove the list lookup and replace it with simply:

	kmod_module_new_from_name(ctx->kmod_ctx, mod_name, &kmod);

It would clean up the module related flows, but is there any
disadvantage to doing this?