Re: [PATCH v3] firmware_loader: allow firmware_class.path to take multiple paths

[Jeff Layton <jlayton@kernel.org>]

On Thu, 2026-03-19 at 07:23 +0100, Greg Kroah-Hartman wrote:
> On Wed, Mar 18, 2026 at 03:54:02PM -0400, Jeff Layton wrote:
> > Refactor fw_get_filesystem_firmware() by extracting the per-path
> > firmware loading logic into a new fw_try_firmware_path() helper.
> > 
> > Use this helper to parse fw_path_para for ':'-separated paths,
> > trying each one before falling through to the default firmware
> > search paths. This allows users to specify multiple custom firmware
> > directories via firmware_class.path, e.g.:
> > 
> >   firmware_class.path=/custom/path1:/custom/path2
> > 
> > A backslash can be used as an escape character, allowing a literal
> > ':' ("\:") or literal '\' ("\\") to be embedded in a pathname.
> 
> This is a mess, what could go wrong embedding another parser in the
> kernel :)
> 
> Let's step back, why is this needed at all?  The kernel already supports
> multiple standard locations for firmware paths, and one custom location.
> Why do we now need more than that?  What changed to require this and who
> is going to use it (and support it, and actually test it?)
> 

We have at least one internal user that requested the ability to do
this. I'll see if they can articulate their use-case better.

> We really want to make the number of firmware paths less, not more.  But
> if we _really_ need multiple paths, isn't it simpler to just have an
> array of paths here, not be forced to parse escape codes like you are
> now doing?
> 

How would one feed an array of paths to the module without delimiting
them in some fashion?
-- 
Jeff Layton <jlayton@kernel.org>