usb: dwc3: gadget: Allow runtime suspend if UDC unbinded

commit 77adb8bdf4227257e26b7ff67272678e66a0b250 upstream.

The DWC3 runtime suspend routine checks for the USB connected parameter to
determine if the controller can enter into a low power state.  The
connected state is only set to false after receiving a disconnect event.
However, in the case of a device initiated disconnect (i.e. UDC unbind),
the controller is halted and a disconnect event is never generated.  Set
the connected flag to false if issuing a device initiated disconnect to
allow the controller to be suspended.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/1609283136-22140-2-git-send-email-wcheng@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 56f7235..ef8ecaf 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2126,6 +2126,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
        }
 
        /*
+        * Check the return value for successful resume, or error.  For a
+        * successful resume, the DWC3 runtime PM resume routine will handle
+        * the run stop sequence, so avoid duplicate operations here.
+        */
+       ret = pm_runtime_get_sync(dwc->dev);
+       if (!ret || ret < 0) {
+               pm_runtime_put(dwc->dev);
+               return 0;
+       }
+
+       /*
         * Synchronize any pending event handling before executing the controller
         * halt routine.
         */
@@ -2163,12 +2174,14 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
                        dwc->ev_buf->lpos = (dwc->ev_buf->lpos + count) %
                                                dwc->ev_buf->length;
                }
+               dwc->connected = false;
        } else {
                __dwc3_gadget_start(dwc);
        }
 
        ret = dwc3_gadget_run_stop(dwc, is_on, false);
        spin_unlock_irqrestore(&dwc->lock, flags);
+       pm_runtime_put(dwc->dev);
 
        return ret;
 }