[PATCH 5.4 06/27] usb: dwc3: gadget: Allow runtime suspend if UDC unbinded

Greg Kroah-Hartman
2021-08-13T15:17:06Z

From: Wesley Cheng <wcheng@codeaurora.org>

[ Upstream commit 77adb8bdf4227257e26b7ff67272678e66a0b250 ]

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>
---
drivers/usb/dwc3/gadget.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2018,6 +2018,17 @@ static int dwc3_gadget_pullup(struct usb
}

/*
+ * 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.
*/
@@ -2055,10 +2066,12 @@ static int dwc3_gadget_pullup(struct usb
dwc->ev_buf->lpos = (dwc->ev_buf->lpos + count) %
dwc->ev_buf->length;
}
+ dwc->connected = false;
}

ret = dwc3_gadget_run_stop(dwc, is_on, false);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);

return ret;
}