From 9f45581f5eec6786c6eded2b3c85345d82a910c9 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Mon, 21 Jan 2019 13:01:16 +0200 Subject: usb: dwc3: gadget: early giveback if End Transfer already completed There is a rare race condition that may happen during a Disconnect Interrupt if we have a started request that happens to be dequeued *after* completion of End Transfer command. If that happens, that request will be left waiting for completion of an End Transfer command that will never happen. If End Transfer command has already completed before, we are safe to giveback the request straight away. Tested-by: Thinh Nguyen Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/gadget.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/usb/dwc3') diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index eaeea8ff5191..b82a8885747d 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1550,7 +1550,10 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, goto out0; dwc3_gadget_move_cancelled_request(req); - goto out0; + if (dep->flags & DWC3_EP_TRANSFER_STARTED) + goto out0; + else + goto out1; } dev_err(dwc->dev, "request %pK was not queued to %s\n", request, ep->name); @@ -1558,6 +1561,7 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, goto out0; } +out1: dwc3_gadget_giveback(dep, req, -ECONNRESET); out0: -- cgit v1.2.3-58-ga151