[PATCH 5/5] usb: dwc3: rockchip: fix USB-C reconnect in gadget mode

[Thinh Nguyen]

On Tue, Sep 15, 2026, Sebastian Reichel wrote:
> When USB-C is configured in gadget mode and the cable is unplugged
> the USB controller is suspended. After plugging in the cable again,
> the USB controller stays suspended and thus the port status remains
> not-attached.
> 
> Fix this by triggering a runtime PM resume when the role is changed.
> The Runtime PM reference counter is immediately decreased again - the
> auto-suspend time is big enough to detect the connection status, which
> will then keep its own reference.
> 
> Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
> ---
>  drivers/usb/dwc3/dwc3-rockchip.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/dwc3-rockchip.c b/drivers/usb/dwc3/dwc3-rockchip.c
> index 7bdd6e2eb22d..bedec3295bb1 100644
> --- a/drivers/usb/dwc3/dwc3-rockchip.c
> +++ b/drivers/usb/dwc3/dwc3-rockchip.c
> @@ -25,8 +25,17 @@ struct dwc3_rockchip {
>  	struct dwc3		dwc;
>  	struct dwc3_rk_phy_nb	usb3_phy_nb[DWC3_USB3_MAX_PORTS];
>  	u8			phy_reset_active;
> +	enum usb_role		role;
>  };
>  
> +static void dwc3_rockchip_vbus_handler(struct dwc3 *dwc, bool present)
> +{
> +	if (!dwc->gadget || !dwc->gadget_driver)
> +		return;
> +
> +	usb_udc_vbus_handler(dwc->gadget, present);
> +}
> +
>  static int dwc3_usb3_phy_notify(struct notifier_block *nb,
>  				unsigned long action, void *data)
>  {
> @@ -57,6 +66,8 @@ static int dwc3_usb3_phy_notify(struct notifier_block *nb,
>  		if (!ret)
>  			return NOTIFY_OK;
>  
> +		dwc3_rockchip_vbus_handler(dwc, false);
> +
>  		/*
>  		 * Assert USB3 PHY soft reset within DWC3 before the external
>  		 * PHY resets. This disconnects the PIPE interface, preventing
> @@ -69,6 +80,7 @@ static int dwc3_usb3_phy_notify(struct notifier_block *nb,
>  		reg |= DWC3_GUSB3PIPECTL_PHYSOFTRST;
>  		dwc3_writel(dwc, DWC3_GUSB3PIPECTL(port), reg);
>  		spin_unlock_irqrestore(&dwc->lock, flags);
> +
>  		break;
>  
>  	case PHY_NOTIFY_POST_RESET:
> @@ -89,6 +101,8 @@ static int dwc3_usb3_phy_notify(struct notifier_block *nb,
>  		dwc3_writel(dwc, DWC3_GUSB3PIPECTL(port), reg);
>  		spin_unlock_irqrestore(&dwc->lock, flags);
>  
> +		dwc3_rockchip_vbus_handler(dwc, dwc_rk->role == USB_ROLE_DEVICE);
> +
>  		pm_runtime_put_autosuspend(dwc->dev);
>  		break;
>  	}
> @@ -130,7 +144,16 @@ static int dwc3_rk_phy_register_notifiers(struct dwc3 *dwc)
>  	return devm_add_action_or_reset(dwc->dev, dwc3_rk_phy_unregister_notifiers, dwc_rk);
>  }
>  
> +static void dwc3_rockchip_set_role(struct dwc3 *dwc, enum usb_role role)
> +{
> +	struct dwc3_rockchip *dwc_rk = container_of(dwc, struct dwc3_rockchip, dwc);
> +
> +	dwc_rk->role = role;
> +	dwc3_rockchip_vbus_handler(dwc, role == USB_ROLE_DEVICE);
> +}
> +
>  static struct dwc3_glue_ops dwc3_rockchip_glue_ops = {
> +	.pre_set_role = dwc3_rockchip_set_role,
>  	.post_phy_registration = dwc3_rk_phy_register_notifiers,
>  };
>  
> 
> -- 
> 2.53.0
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen at synopsys.com>

Thanks,
Thinh