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

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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 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?

thanks,

greg k-h