>
>When the system goes to suspend, if the controller is at device mode with
>cable connecting to host, the call stack is: cdns3_suspend->
>cdns3_gadget_suspend -> cdns3_disconnect_gadget, after cdns3_disconnect_gadget
>is called, it owns lock wrongly, it causes the system being deadlock after
>resume due to at cdns3_device_thread_irq_handler, it tries to get the lock,
>but can't get it forever.
>
>To fix it, we delete the unlock-lock operations at cdns3_disconnect_gadget,
>and do it at the caller.
>
>Fixes: b1234e3b3b26 ("usb: cdns3: add runtime PM support")
>Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
Acked-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
>---
>Changes for v3:
>- Add __must_hold sparse checker
>
> drivers/usb/cdns3/gadget.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
>index 6ff3aa3db497..8e02ccdbd4c5 100644
>--- a/drivers/usb/cdns3/gadget.c
>+++ b/drivers/usb/cdns3/gadget.c
>@@ -1744,11 +1744,8 @@ static int cdns3_check_ep_interrupt_proceed(struct cdns3_endpoint *priv_ep)
>
> static void cdns3_disconnect_gadget(struct cdns3_device *priv_dev)
> {
>- if (priv_dev->gadget_driver && priv_dev->gadget_driver->disconnect) {
>- spin_unlock(&priv_dev->lock);
>+ if (priv_dev->gadget_driver && priv_dev->gadget_driver->disconnect)
> priv_dev->gadget_driver->disconnect(&priv_dev->gadget);
>- spin_lock(&priv_dev->lock);
>- }
> }
>
> /**
>@@ -1759,6 +1756,7 @@ static void cdns3_disconnect_gadget(struct cdns3_device *priv_dev)
> */
> static void cdns3_check_usb_interrupt_proceed(struct cdns3_device *priv_dev,
> u32 usb_ists)
>+__must_hold(&priv_dev->lock)
> {
> int speed = 0;
>
>@@ -1783,7 +1781,9 @@ static void cdns3_check_usb_interrupt_proceed(struct cdns3_device *priv_dev,
>
> /* Disconnection detected */
> if (usb_ists & (USB_ISTS_DIS2I | USB_ISTS_DISI)) {
>+ spin_unlock(&priv_dev->lock);
> cdns3_disconnect_gadget(priv_dev);
>+ spin_lock(&priv_dev->lock);
> priv_dev->gadget.speed = USB_SPEED_UNKNOWN;
> usb_gadget_set_state(&priv_dev->gadget, USB_STATE_NOTATTACHED);
> cdns3_hw_reset_eps_config(priv_dev);
>@@ -3263,10 +3263,13 @@ static int __cdns3_gadget_init(struct cdns3 *cdns)
> }
>
> static int cdns3_gadget_suspend(struct cdns3 *cdns, bool do_wakeup)
>+__must_hold(&cdns->lock)
> {
> struct cdns3_device *priv_dev = cdns->gadget_dev;
>
>+ spin_unlock(&cdns->lock);
> cdns3_disconnect_gadget(priv_dev);
>+ spin_lock(&cdns->lock);
>
> priv_dev->gadget.speed = USB_SPEED_UNKNOWN;
> usb_gadget_set_state(&priv_dev->gadget, USB_STATE_NOTATTACHED);
>--
>2.17.1
