[PATCH v2] usb: gadget: udc: skip pullup() if already connected

[PATCH v2] usb: gadget: udc: skip pullup() if already connected

[Xu Yang]

The device controller may update vbus status via usb_udc_vbus_handler(),
which tries to connect the gadget even though gadget_bind_driver() has
already called usb_udc_connect_control_locked(). This causes pullup() to
be called twice. Avoid this by checking if gadget->connected is true.

This also set gadget->connected as false in usb_gadget_activate() if it
became connected while it was being deactivated. Otherwise,
usb_gadget_connect_locked will return early and pullup() won't be called.

Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

---
Changes in v2:
 - reset gadget->connected as false before calling usb_gadget_connect_locked()
---
 drivers/usb/gadget/udc/core.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index e8861eaad907..60340ff9edbf 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -712,6 +712,9 @@ static int usb_gadget_connect_locked(struct usb_gadget *gadget)
 		goto out;
 	}
 
+	if (gadget->connected)
+		goto out;
+
 	if (gadget->deactivated || !gadget->udc->allow_connect || !gadget->udc->started) {
 		/*
 		 * If the gadget isn't usable (because it is deactivated,
@@ -885,8 +888,10 @@ int usb_gadget_activate(struct usb_gadget *gadget)
 	 * If gadget has been connected before deactivation, or became connected
 	 * while it was being deactivated, we call usb_gadget_connect().
 	 */
-	if (gadget->connected)
+	if (gadget->connected) {
+		gadget->connected = false;
 		ret = usb_gadget_connect_locked(gadget);
+	}
 
 unlock:
 	mutex_unlock(&gadget->udc->connect_lock);
-- 
2.34.1

Re: [PATCH v2] usb: gadget: udc: skip pullup() if already connected

[Alan Stern]

On Thu, Apr 23, 2026 at 05:53:55PM +0800, Xu Yang wrote:
> The device controller may update vbus status via usb_udc_vbus_handler(),
> which tries to connect the gadget even though gadget_bind_driver() has
> already called usb_udc_connect_control_locked(). This causes pullup() to
> be called twice. Avoid this by checking if gadget->connected is true.
> 
> This also set gadget->connected as false in usb_gadget_activate() if it
> became connected while it was being deactivated. Otherwise,
> usb_gadget_connect_locked will return early and pullup() won't be called.
> 
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

Reviewed-by: Alan Stern <stern@rowland.harvard.edu>

> ---
> Changes in v2:
>  - reset gadget->connected as false before calling usb_gadget_connect_locked()
> ---
>  drivers/usb/gadget/udc/core.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> index e8861eaad907..60340ff9edbf 100644
> --- a/drivers/usb/gadget/udc/core.c
> +++ b/drivers/usb/gadget/udc/core.c
> @@ -712,6 +712,9 @@ static int usb_gadget_connect_locked(struct usb_gadget *gadget)
>  		goto out;
>  	}
>  
> +	if (gadget->connected)
> +		goto out;
> +
>  	if (gadget->deactivated || !gadget->udc->allow_connect || !gadget->udc->started) {
>  		/*
>  		 * If the gadget isn't usable (because it is deactivated,
> @@ -885,8 +888,10 @@ int usb_gadget_activate(struct usb_gadget *gadget)
>  	 * If gadget has been connected before deactivation, or became connected
>  	 * while it was being deactivated, we call usb_gadget_connect().
>  	 */
> -	if (gadget->connected)
> +	if (gadget->connected) {
> +		gadget->connected = false;
>  		ret = usb_gadget_connect_locked(gadget);
> +	}
>  
>  unlock:
>  	mutex_unlock(&gadget->udc->connect_lock);
> -- 
> 2.34.1
> 
>