Re: [PATCH] platform/x86: intel: chtwc_int33fe: don't dereference swnode args

[Hans de Goede <hansg@kernel.org>]

Hi,

On 21-Nov-25 11:04 AM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> 
> Members of struct software_node_ref_args should not be dereferenced
> directly but set using the provided macros. Commit d7cdbbc93c56
> ("software node: allow referencing firmware nodes") changed the name of
> the software node member and caused a build failure. Remove all direct
> dereferences of the ref struct as a fix.
> 
> However, this driver also seems to abuse the software node interface by
> waiting for a node with an arbitrary name "intel-xhci-usb-sw" to appear
> in the system before setting up the reference for the I2C device, while
> the actual software node already exists in the intel-xhci-usb-role-switch
> module and should be used to set up a static reference. Add a FIXME for
> a future improvement.
> 
> Fixes: d7cdbbc93c56 ("software node: allow referencing firmware nodes")
> Fixes: 53c24c2932e5 ("platform/x86: intel_cht_int33fe: use inline reference properties")
> Cc: stable@vger.kernel.org
> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> Closes: https://lore.kernel.org/all/20251121111534.7cdbfe5c@canb.auug.org.au/
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> ---
> This should go into the reset tree as a fix to the regression introduced
> by the reset-gpio driver rework.

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>

Also ack for merging this through the reset tree.

Ilpo please do *not* pick this one up as it will be merged
through the reset tree.

Regards,

Hans




> ---
>  drivers/platform/x86/intel/chtwc_int33fe.c | 29 ++++++++++++++++++++---------
>  1 file changed, 20 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/platform/x86/intel/chtwc_int33fe.c b/drivers/platform/x86/intel/chtwc_int33fe.c
> index 29e8b5432f4c9eea7dc45b83d94c0e00373f901b..d183aa53c318ba8d57c7124c38506e6956b3ee36 100644
> --- a/drivers/platform/x86/intel/chtwc_int33fe.c
> +++ b/drivers/platform/x86/intel/chtwc_int33fe.c
> @@ -77,7 +77,7 @@ static const struct software_node max17047_node = {
>   * software node.
>   */
>  static struct software_node_ref_args fusb302_mux_refs[] = {
> -	{ .node = NULL },
> +	SOFTWARE_NODE_REFERENCE(NULL),
>  };
>  
>  static const struct property_entry fusb302_properties[] = {
> @@ -190,11 +190,6 @@ static void cht_int33fe_remove_nodes(struct cht_int33fe_data *data)
>  {
>  	software_node_unregister_node_group(node_group);
>  
> -	if (fusb302_mux_refs[0].node) {
> -		fwnode_handle_put(software_node_fwnode(fusb302_mux_refs[0].node));
> -		fusb302_mux_refs[0].node = NULL;
> -	}
> -
>  	if (data->dp) {
>  		data->dp->secondary = NULL;
>  		fwnode_handle_put(data->dp);
> @@ -202,7 +197,15 @@ static void cht_int33fe_remove_nodes(struct cht_int33fe_data *data)
>  	}
>  }
>  
> -static int cht_int33fe_add_nodes(struct cht_int33fe_data *data)
> +static void cht_int33fe_put_swnode(void *data)
> +{
> +	struct fwnode_handle *fwnode = data;
> +
> +	fwnode_handle_put(fwnode);
> +	fusb302_mux_refs[0] = SOFTWARE_NODE_REFERENCE(NULL);
> +}
> +
> +static int cht_int33fe_add_nodes(struct device *dev, struct cht_int33fe_data *data)
>  {
>  	const struct software_node *mux_ref_node;
>  	int ret;
> @@ -212,17 +215,25 @@ static int cht_int33fe_add_nodes(struct cht_int33fe_data *data)
>  	 * until the mux driver has created software node for the mux device.
>  	 * It means we depend on the mux driver. This function will return
>  	 * -EPROBE_DEFER until the mux device is registered.
> +	 *
> +	 * FIXME: the relevant software node exists in intel-xhci-usb-role-switch
> +	 * and - if exported - could be used to set up a static reference.
>  	 */
>  	mux_ref_node = software_node_find_by_name(NULL, "intel-xhci-usb-sw");
>  	if (!mux_ref_node)
>  		return -EPROBE_DEFER;
>  
> +	ret = devm_add_action_or_reset(dev, cht_int33fe_put_swnode,
> +				       software_node_fwnode(mux_ref_node));
> +	if (ret)
> +		return ret;
> +
>  	/*
>  	 * Update node used in "usb-role-switch" property. Note that we
>  	 * rely on software_node_register_node_group() to use the original
>  	 * instance of properties instead of copying them.
>  	 */
> -	fusb302_mux_refs[0].node = mux_ref_node;
> +	fusb302_mux_refs[0] = SOFTWARE_NODE_REFERENCE(mux_ref_node);
>  
>  	ret = software_node_register_node_group(node_group);
>  	if (ret)
> @@ -345,7 +356,7 @@ static int cht_int33fe_typec_probe(struct platform_device *pdev)
>  		return fusb302_irq;
>  	}
>  
> -	ret = cht_int33fe_add_nodes(data);
> +	ret = cht_int33fe_add_nodes(dev, data);
>  	if (ret)
>  		return ret;
>  
> 
> ---
> base-commit: cba510406ba76569782ead6007a0e4eb5d34a7ab
> change-id: 20251121-int33fe-swnode-fix-e896da458560
> 
> Best regards,