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

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

On Wed, Mar 18, 2026 at 08:25:54AM -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
> 
> Suggested-by: Michal Grzedzicki <mge@meta.com>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> This is something Michal had asked for last year, and I just got around
> to implementing. Tested with a dummy module that calls
> request_firmware().
> ---
>  drivers/base/firmware_loader/main.c | 197 +++++++++++++++++++++---------------
>  1 file changed, 118 insertions(+), 79 deletions(-)
> 
> diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
> index a11b30dda23be563bd55f25474ceff2153ddd667..5328d28a2141e85265e1bcc20e995ce4c5517c36 100644
> --- a/drivers/base/firmware_loader/main.c
> +++ b/drivers/base/firmware_loader/main.c
> @@ -470,7 +470,6 @@ static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
>  /* direct firmware loading support */
>  static char fw_path_para[256];
>  static const char * const fw_path[] = {
> -	fw_path_para,
>  	"/lib/firmware/updates/" UTS_RELEASE,
>  	"/lib/firmware/updates",
>  	"/lib/firmware/" UTS_RELEASE,
> @@ -480,10 +479,83 @@ static const char * const fw_path[] = {
>  /*
>   * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
>   * from kernel command line because firmware_class is generally built in
> - * kernel instead of module.
> + * kernel instead of module. Multiple paths can be separated by ';'.
>   */
>  module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
> -MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
> +MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path, multiple paths can be separated by ';'");

Ah, you documented it here, sorry, I missed that.

But still, why ';'?

greg k-h