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usb: dwc3: gadget: simplify __dwc3_gadget_ep_queue()

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Many of the comments in that function are really
outdated and don't match what the driver is
doing. Moreover, recent patches combined programming
model for all non-control endpoints, this gives us
an opportunity to get rid of our special cases in
__dwc3_gadget_ep_queue().

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Felipe Balbi 2016-08-11 14:27:52 +03:00
parent 45438a0cd9
commit 08a36b5438
1 changed files with 7 additions and 76 deletions
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83
drivers/usb/dwc3/gadget.c
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@ -1063,18 +1063,6 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
trace_dwc3_ep_queue(req);
/*
* We only add to our list of requests now and
* start consuming the list once we get XferNotReady
* IRQ.
*
* That way, we avoid doing anything that we don't need
* to do now and defer it until the point we receive a
* particular token from the Host side.
*
* This will also avoid Host cancelling URBs due to too
* many NAKs.
*/
ret = usb_gadget_map_request(&dwc->gadget, &req->request,
dep->direction);
if (ret)
@ -1082,73 +1070,16 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
list_add_tail(&req->list, &dep->pending_list);
/*
* If there are no pending requests and the endpoint isn't already
* busy, we will just start the request straight away.
*
* This will save one IRQ (XFER_NOT_READY) and possibly make it a
* little bit faster.
*/
if (!usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
ret = __dwc3_gadget_kick_transfer(dep, 0);
goto out;
}
/*
* There are a few special cases:
*
* 1. XferNotReady with empty list of requests. We need to kick the
* transfer here in that situation, otherwise we will be NAKing
* forever. If we get XferNotReady before gadget driver has a
* chance to queue a request, we will ACK the IRQ but won't be
* able to receive the data until the next request is queued.
* The following code is handling exactly that.
*
*/
if (dep->flags & DWC3_EP_PENDING_REQUEST) {
/*
* If xfernotready is already elapsed and it is a case
* of isoc transfer, then issue END TRANSFER, so that
* you can receive xfernotready again and can have
* notion of current microframe.
*/
if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
if (list_empty(&dep->started_list)) {
dwc3_stop_active_transfer(dwc, dep->number, true);
dep->flags = DWC3_EP_ENABLED;
}
return 0;
}
ret = __dwc3_gadget_kick_transfer(dep, 0);
if (!ret)
dep->flags &= ~DWC3_EP_PENDING_REQUEST;
goto out;
}
/*
* 2. XferInProgress on Isoc EP with an active transfer. We need to
* kick the transfer here after queuing a request, otherwise the
* core may not see the modified TRB(s).
*/
if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
(dep->flags & DWC3_EP_BUSY) &&
!(dep->flags & DWC3_EP_MISSED_ISOC)) {
WARN_ON_ONCE(!dep->resource_index);
ret = __dwc3_gadget_kick_transfer(dep, dep->resource_index);
goto out;
dep->flags & DWC3_EP_PENDING_REQUEST) {
if (list_empty(&dep->started_list)) {
dwc3_stop_active_transfer(dwc, dep->number, true);
dep->flags = DWC3_EP_ENABLED;
}
return 0;
}
/*
* 4. Stream Capable Bulk Endpoints. We need to start the transfer
* right away, otherwise host will not know we have streams to be
* handled.
*/
if (dep->stream_capable)
ret = __dwc3_gadget_kick_transfer(dep, 0);
out:
ret = __dwc3_gadget_kick_transfer(dep, 0);
if (ret && ret != -EBUSY)
dwc3_trace(trace_dwc3_gadget,
"%s: failed to kick transfers",