Re: [PATCH] usb: typec: retimer: Add missing id check in match callback

[Heikki Krogerus]

On Mon, Jul 25, 2022 at 04:31:29PM -0400, Nícolas F. R. A. Prado wrote:
> The fwnode_connection_find_match() function handles two cases: named
> references and graph endpoints. In the second case, the match function
> passed in is called with the id to check for the match. However, the
> match function for the recently added type-c retimer class assumes the
> connection has already been matched (which is only true for the first
> case).
> 
> The result is that with that change, all type-c nodes with graph
> endpoints defer probe indefinitely, independently of having a retimer
> connection or not.
> 
> Add the missing check, like is done by the type-c mux and usb role
> switch code, to fix the issue.
> 
> Fixes: ddaf8d96f93b ("usb: typec: Add support for retimers")
> Signed-off-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>

Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>

> ---
> 
>  drivers/usb/typec/retimer.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/typec/retimer.c b/drivers/usb/typec/retimer.c
> index 051eaa7d2899..2003731f1bee 100644
> --- a/drivers/usb/typec/retimer.c
> +++ b/drivers/usb/typec/retimer.c
> @@ -36,8 +36,13 @@ static int retimer_fwnode_match(struct device *dev, const void *fwnode)
>  
>  static void *typec_retimer_match(struct fwnode_handle *fwnode, const char *id, void *data)
>  {
> -	struct device *dev  = class_find_device(&retimer_class, NULL, fwnode,
> -						retimer_fwnode_match);
> +	struct device *dev;
> +
> +	if (id && !fwnode_property_present(fwnode, id))
> +		return NULL;
> +
> +	dev = class_find_device(&retimer_class, NULL, fwnode,
> +				retimer_fwnode_match);
>  
>  	return dev ? to_typec_retimer(dev) : ERR_PTR(-EPROBE_DEFER);
>  }

thanks,

-- 
heikki