Unverified Commit e11d2bf2 authored by Peter Chen's avatar Peter Chen
Browse files

usb: cdns3: gadget: own the lock wrongly at the suspend routine 



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: b1234e3b ("usb: cdns3: add runtime PM support")
Acked-by: default avatarPawel Laszczak <pawell@cadence.com>
Signed-off-by: default avatarPeter Chen <peter.chen@nxp.com>
parent 52d39677

drivers/usb/cdns3/gadget.c

+7 −4
Original line number Diff line number Diff line
@@ -1750,11 +1750,8 @@ 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);

	}

}



/**
@@ -1765,6 +1762,7 @@ 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;
@@ -1789,7 +1787,9 @@ 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);
@@ -3275,10 +3275,13 @@ err0: 
}



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);

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