Re: [PATCH v5 2/4] usb: hub: add infrastructure to pass onboard_dev port features

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

On Mon, Feb 23, 2026 at 12:27:35PM +0100, Marco Felsch wrote:
> On board devices may require special handling for en-/disable port
> features due to PCB design decisions e.g. enable/disable the VBUS power
> on the port via a host controlled regulator or GPIO.
> 
> This commit adds the necessary infrastructure to prepare the common code
> base for such use-cases.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  drivers/usb/core/hub.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++--
>  drivers/usb/core/hub.h |  2 ++
>  include/linux/usb.h    |  3 +++
>  3 files changed, 58 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 24960ba9caa915f12a4f5582269808fdebd1ee11..9fdfd2f0aacc9b1994cd3761330968e052167c67 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -453,9 +453,19 @@ static int clear_hub_feature(struct usb_device *hdev, int feature)
>   */
>  int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
>  {
> -	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
> +	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
> +	int ret;
> +
> +	ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
>  		USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
>  		NULL, 0, 1000);
> +	if (ret)
> +		return ret;
> +
> +	if (hub->onboard_hub_clear_port_feature)
> +		ret = hub->onboard_hub_clear_port_feature(hdev, feature, port1);
> +
> +	return ret;
>  }
>  
>  /*
> @@ -463,9 +473,19 @@ int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
>   */
>  static int set_port_feature(struct usb_device *hdev, int port1, int feature)
>  {
> -	return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
> +	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
> +	int ret;
> +
> +	ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
>  		USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
>  		NULL, 0, 1000);
> +	if (ret)
> +		return ret;
> +
> +	if (hub->onboard_hub_set_port_feature)
> +		ret = hub->onboard_hub_set_port_feature(hdev, feature, port1);
> +
> +	return ret;
>  }
>  
>  static char *to_led_name(int selector)
> @@ -6545,6 +6565,37 @@ void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
>  	}
>  }
>  
> +/**
> + * usb_hub_register_port_feature_hooks - Register port set/get feature hooks
> + * @hdev: USB device belonging to the usb hub
> + * @set_port_feature: set_feature hook which gets called by the hub core
> + * @clear_port_feature: clear_feature hook which gets called by the hub core
> + *
> + * Register set/get_port_feature hooks for a onboard_dev hub.
> + */
> +void usb_hub_register_port_feature_hooks(struct usb_device *hdev,
> +		int (*set_port_feature)(struct usb_device *, int, int),
> +		int (*clear_port_feature)(struct usb_device *, int, int))

This should be a structure, don't force function pointers to be passed
in a function, that way lies madness :)

thanks,

greg k-h