Re: [PATCH v5 1/4] usb: port: track the disabled state

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

On Mon, Feb 23, 2026 at 12:27:34PM +0100, Marco Felsch wrote:
> The disable state isn't tracked at the moment, instead the state is
> directly passed to the hub driver. Change this behavior to only trigger
> the hub if a state change happened. Exit early in case of no state
> changes but don't return an error.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  drivers/usb/core/hub.h  | 2 ++
>  drivers/usb/core/port.c | 6 ++++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> index 9ebc5ef54a325d63e01b0deb59a1853d2b13c8d5..297adf2c6078809ca582104f228e5222c464f999 100644
> --- a/drivers/usb/core/hub.h
> +++ b/drivers/usb/core/hub.h
> @@ -97,6 +97,7 @@ struct usb_hub {
>   * @usb3_lpm_u2_permit: whether USB3 U2 LPM is permitted.
>   * @early_stop: whether port initialization will be stopped earlier.
>   * @ignore_event: whether events of the port are ignored.
> + * @disabled: whether the port is disabled
>   */
>  struct usb_port {
>  	struct usb_device *child;
> @@ -118,6 +119,7 @@ struct usb_port {
>  	unsigned int is_superspeed:1;
>  	unsigned int usb3_lpm_u1_permit:1;
>  	unsigned int usb3_lpm_u2_permit:1;
> +	unsigned int disabled:1;
>  };
>  
>  #define to_usb_port(_dev) \
> diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
> index 44e38f922bc553adee64b35c536dfd4154a42d8a..86e9d6d0c0f505782569565fde8e4a46b06b8b4d 100644
> --- a/drivers/usb/core/port.c
> +++ b/drivers/usb/core/port.c
> @@ -117,6 +117,10 @@ static ssize_t disable_store(struct device *dev, struct device_attribute *attr,
>  	if (rc)
>  		return rc;
>  
> +	/* Early quit if no change was detected */
> +	if (port_dev->disabled == disabled)
> +		return count;
> +

This will change behavior where someone tells the port to be enabled
again, when it already is.  Is that ok?

thanks,

greg k-h