Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 2 Aug 2022 10:18:46 +0300
From:   Heikki Krogerus <heikki.krogerus@linux.intel.com>
To:     =?iso-8859-1?Q?N=EDcolas_F=2E_R=2E_A=2E?= Prado 
        <nfraprado@collabora.com>
Cc:     kernel@collabora.com,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Prashant Malani <pmalani@chromium.org>,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: [PATCH] usb: typec: retimer: Add missing id check in match
 callback
Message-ID: <YujP1oOHojuB9iXa@kuha.fi.intel.com>
References: <20220725203129.1973260-1-nfraprado@collabora.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20220725203129.1973260-1-nfraprado@collabora.com>
Precedence: bulk

On Mon, Jul 25, 2022 at 04:31:29PM -0400, N?colas 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: N?colas F. R. A. Prado <nfraprado@collabora.com>

Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
> 
>  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