usb: dwc3: Prevent indefinite sleep in _dwc3_set_mode during suspend/resume

In the following test we get stuck by sleeping forever in _dwc3_set_mode()
after which dual-role switching doesn't work.

On dra7-evm's dual-role port,
- Load g_zero gadget driver and enumerate to host
- suspend to mem
- disconnect USB cable to host and connect otg cable with Pen drive in it.
- resume system
- we sleep indefinitely in _dwc3_set_mode due to.
  dwc3_gadget_exit()->usb_del_gadget_udc()->udc_stop()->
	dwc3_gadget_stop()->wait_event_lock_irq()

To fix this instead of waiting indefinitely with wait_event_lock_irq()
we use wait_event_interruptible_lock_irq_timeout() and print
and error message if there was a timeout.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 2bda4eb1e9ac175858189c498af875ed8315df80..7c3a6e4ea2a62752d8aba4cee0990e25fa8cac19 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1950,6 +1950,7 @@ static int dwc3_gadget_stop(struct usb_gadget *g)
        struct dwc3             *dwc = gadget_to_dwc(g);
        unsigned long           flags;
        int                     epnum;
+       u32                     tmo_eps = 0;
 
        spin_lock_irqsave(&dwc->lock, flags);
 
@@ -1960,6 +1961,7 @@ static int dwc3_gadget_stop(struct usb_gadget *g)
 
        for (epnum = 2; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
                struct dwc3_ep  *dep = dwc->eps[epnum];
+               int ret;
 
                if (!dep)
                        continue;
@@ -1967,9 +1969,24 @@ static int dwc3_gadget_stop(struct usb_gadget *g)
                if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING))
                        continue;
 
-               wait_event_lock_irq(dep->wait_end_transfer,
-                                   !(dep->flags & DWC3_EP_END_TRANSFER_PENDING),
-                                   dwc->lock);
+               ret = wait_event_interruptible_lock_irq_timeout(dep->wait_end_transfer,
+                           !(dep->flags & DWC3_EP_END_TRANSFER_PENDING),
+                           dwc->lock, msecs_to_jiffies(5));
+
+               if (ret <= 0) {
+                       /* Timed out or interrupted! There's nothing much
+                        * we can do so we just log here and print which
+                        * endpoints timed out at the end.
+                        */
+                       tmo_eps |= 1 << epnum;
+                       dep->flags &= DWC3_EP_END_TRANSFER_PENDING;
+               }
+       }
+
+       if (tmo_eps) {
+               dev_err(dwc->dev,
+                       "end transfer timed out on endpoints 0x%x [bitmap]\n",
+                       tmo_eps);
        }
 
 out: