Queueing the same request twice can introduce hard-to-debug problems. At least one function driver - Android's f_mtp.c - is known to cause this problem. While that function is out-of-tree, this is a problem that's easy enough to avoid. Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> --- drivers/usb/dwc3/gadget.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index da6c02ec6776..74db274786bc 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1436,6 +1436,11 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) &req->request, req->dep->name)) return -EINVAL; + if (WARN(req->status < DWC3_REQUEST_STATUS_COMPLETED, + "%s: request %pK already in flight\n", + dep->name, &req->request)) + return -EINVAL; + pm_runtime_get(dwc->dev); req->request.actual = 0; -- 2.20.1
