Messages in this thread | | | From | Felipe Balbi <> | Subject | Re: [PATCH] usb: dwc3: ep0: Fix the possible missed request for handling delay STATUS phase | Date | Tue, 28 Feb 2017 13:56:39 +0200 |
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Hi,
Alan Stern <stern@rowland.harvard.edu> writes: >> So I am not sure how the Gadget driver can figure out that it needs to >> usb_ep_queue() another request for status stage when handling the >> no-data control? > > Gadget drivers already queue status-stage requests for no-data > control-OUT requests. The difficulty comes when you want to handle an > IN request or an OUT request with a data stage.
I don't see a difficulty there. Gadget driver will see wLength and notice it needs both data and status stages, then it does:
usb_ep_queue(ep0, data_req, GFP_KERNEL); usb_ep_queue(ep0, status_req, GFP_KERNEL);
Just needs to prepare both requests and queue them both ahead of time. UDC drivers should hold both requests in their own private list and process one at a time.
-- balbi
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