| Message ID | 20201029095518.24375-1-peter.chen@nxp.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | e11d2bf271589e70ea80a2ee3e116c40fcac62c2 |
| Headers | show |
| Series | [v3,1/1] usb: cdns3: gadget: own the lock wrongly at the suspend routine | expand |
> >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@nxp.com> Acked-by: Pawel Laszczak <pawell@cadence.com> >--- >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
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);
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@nxp.com> --- Changes for v3: - Add __must_hold sparse checker drivers/usb/cdns3/gadget.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)